Vaccine compositions of herpesvirus envelope protein combinations to induce immune response

ABSTRACT

Provided are antigenic compositions and uses thereof that include at least two human herpesvirus (HHV) polypeptides involved in mediating HHV binding, fusion, and entry into host cells, such as gp350, gH, gL, and gB, or nucleic acids encoding the polypeptides. The two HHV polypeptides comprise any combination of: a gB polypeptide; a gp350 polypeptide; a gL polypeptide; and a gH polypeptide, and optionally any one or more of the following polypeptides: gp42, gM, gN, gl, gC, gE, gD, ORF68, BMRF-2, BDLF2, UL128, UL130, UL131A, and gpK8.1. Also disclosed are methods of inducing an immune response or treating or preventing an HHV infection in a subject by administering to the subject at least two of the HHV polypeptides or nucleic acid(s) encoding the same. Methods of passively transferring immunity using high-titer anti-HHV antibodies or immune cells are also disclosed.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of, and relies on the filing dateof, U.S. provisional patent application No. 62/451,396, filed 27 Jan.2017, the entire disclosure of which is incorporated herein byreference.

GOVERNMENT INTEREST

This invention was made with government support under grant Q574LJ15awarded by the Uniformed Services University. The government has certainrights in the invention.

SEQUENCE LISTING

The instant application contains a Sequence Listing which has beensubmitted electronically in ASCII format and is hereby incorporated byreference in its entirety. Said ASCII copy, created on 25 Jan. 2018, isnamed HMJ-153-PCT_SL.txt and is 207,545 bytes in size.

BACKGROUND

Human herpes viruses are a group of enveloped DNA viruses responsiblefor significant global morbidity and mortality in humans. (Eisenberg etal., Viruses, 4:800-32, 2012). There are eight types of known humanherpes virus (HHV), including: (i) Type 1 human herpes virus (HHV-1),which is herpes simplex virus-1 (HSV-1); (ii) HHV-2 which is herpessimplex virus-2 (HSV-2); (iii) HHV-3 which is varicella-Zoster virus(VZV); (iv) HHV-4 which is Epstein Barr virus (EBV); (v) HHV-5, which ishuman cytomegalovirus (HCMV); (vi) HHV-6; (vii) HHV-7; and (viii) HHV-8which is Kaposi's sarcoma-associated herpesvirus (KSHV).

In humans, these viruses are known to cause the following diseases.HSV-1 causes oral herpes, HSV-2 causes genital herpes, and VZV causeschickenpox and shingles. EBV causes infectious mononucleosis and isstrongly associated with several B cell lymphomas, nasopharyngealcarcinoma, and gastric adenocarcinoma. HCMV causes severe infection inimmunosuppressed patients and is the leading non-genetic cause ofhearing loss. HHV-6 and 7 cause roseola infantum (Sixth disease), andHVV-8 causes Kaposi's sarcoma in several clinical settings including inpatients infected with human immunodeficiency virus (HIV).

EBV primarily infects B cells and nasopharyngeal epithelial cells. EBVinfection of B cells is initiated by binding of the EBV envelope proteingp350 to the complement receptor CR2/CD21. (Hutt-Fletcher, J. Virol.,81:7825-32, 2007; and Shannon-Lowe et al., Curr. Opin. Virol., 4:78-84,2014). Upon binding to B cell CR2, EBV gp42 interacts with cell surfaceMHC-II receptors, leading to its association with the heterodimeric EBVgH/gL protein. The heterodimer gH/gL then undergoes a conformationalchange upon binding gp42, leading to activation of the EBV fusionprotein gB, that directly mediates viral-host cell membrane fusion.(Neuhierl et al., Proc. Natl. Acad. Sci. U.S.A., 99:15036-41, 2002).Like EBV, the binding, fusion and host cell entry of other HHV familymembers is mediated primarily by the gB, gH, and gL polypeptides, inconjunction with other accessory proteins, which typically bind todifferent receptors on the host cell surface.

There is currently no prophylactic EBV vaccine in clinical use. Studiesin non-human primates using gp350-based vaccination strategies haveshown protection against EBV-induced lymphoma and EBV replication.(Cohen, Clin. Transl. Immunology, 4:e32, 2015). A phase II clinicaltrial conducted in EBV-seronegative young adults using a recombinantmonomeric gp350 protein versus placebo suggested a partial protectiveeffect of gp350 vaccination on infectious mononucleosis (IM)development. (Sokal et al., J. Infect. Dis., 196:1749-53, 2007; andMoutschen et al., Vaccine, 25:4697-705, 2007). However, the vaccine didnot prevent asymptomatic EBV infection. A phase I trial of recombinantmonomeric gp350 protein given to children with chronic kidney diseasedemonstrated only a minority of subjects developing detectableneutralizing serum anti-gp350 titers. (Rees et al., Transplantation,88:1025-9, 2009).

There is also no prophylactic HCMV vaccine commercially available today.Earlier clinical trials using live attenuated Towne or AD169 HCMV viralvaccines, both of which lacked expression of a pentameric complex(gH/gL/UL128/UL130/UL131A), proved to be ineffective in preventing HCMVinfection in either healthy volunteers or renal transplant recipients,though some efficacy was demonstrated in overt HCMV disease in high riskRecipient-Donor+ renal transplant recipients (Fu et al., Vaccine,32:2525-33, 2014). New HCMV viral strains engineered to express thepentameric complex are currently being evaluated, but safety concernspersist using this approach. A phase II clinical trial using recombinantHCMV gB protein derived from the Towne strain of HCMV (Spaete R R,Transplant Proc., 23:90-6, 1991) demonstrated 50% efficacy in preventingHCMV infection in HCMV seronegative women (Pass R F, J. Clin. Virol., 46Suppl 4:S73-6, 2009) and 50% efficacy in preventing HCMV viremia insolid organ transplantation patients. The HCMV gB protein used in PhaseII clinical trials had been modified to remove the furin cleavage site.Thus, the gB did not assume its native trimeric conformation (Sharma etal., Virology, 435:239-49, 2013). Although these two studies haveencouraged further evaluation of gB as a prophylactic HCMV vaccine, theyindicate a compelling need for a more effective prophylactic vaccineformulation.

WO2014/018858 and WO2015/089340 describe strategies for enhancingimmunity that involve multimerizing antigens. For example, WO2014/018858describes fusion proteins comprising at least two antigens, separated bya linker sequence, and an oligomerization domain, including multimericHHV antigens, such as gp350, gB, gH, and gL. WO2015/089340 describes amodified herpesvirus gB obtained by inserting a peptide linker at thefurin cleavage site in the herpesvirus gB polypeptide extracellulardomain. Inserting the peptide linker removes the furin recognitionsequence, such that expression of the modified herpesvirus gB results inthe production of a homotrimeric gB complex that provides enhancedimmunogenicity.

Combining multiple antigens in a vaccine does not necessarily result inenhanced immunity or even additive effects. In fact, when multipleantigens are co-administered as part of a multicomponent vaccine or aspart of a sequential immunization schedule, the antibody response to oneor more of the antigens may be reduced or diminished due to vaccine orimmune interference. (PrabhuDas et al., Nature Immunology,12(3):189-194, 2011). Similarly, when certain haptens are combined witha carrier protein, the antibody response to the hapten is ofteninhibited if the recipient has been previously immunized with thecarrier protein. This phenomenon has been called carrier-induced epitopesuppression and has been demonstrated to occur with a number ofpeptide-carrier protein conjugates. (Peeters et al., Infection andImmunity, 59(10):3504-3510, 1991). It can also occur when certainsaccharides are combined with a carrier protein, particularly when therecipient is primed with a high dose of the carrier protein (i.e., adose high enough to induce an antibody response to the carrier protein).(Peeters et al., Infection and Immunity, 59(10):3504-3510, 1991). Thus,often times, when two or more antigens are administered to a subject,the antibody response to one or more of the antigens is diminished dueto immune interference. Therefore, when administering multiple proteinsas part of a vaccination or immunization schedule, it is important tocarefully evaluate the interactions between the proteins and how thoseinteractions might affect the immune system's response.

New and improved antigen compositions for enhancing immune responses toHHV are needed.

SUMMARY

Human herpes viruses share a general strategy for infection of hostcells. Specifically, the envelope membrane of the virus fuses with theplasma membrane of the host cell, with subsequent entry into thecytoplasm, or the envelope membrane of the virus fuses with theendosomal membrane after the virus is endocytosed and then enters thecytoplasm of the host cell. The core HHV envelope proteins involved inthe fusion process are the conserved glycoprotein B (gB), glycoprotein H(gH), and glycoprotein L (gL). The gH and gL proteins typically form anoncovalently associated heterodimeric complex during the fusionprocess.

As disclosed in this application, immunization with a combination of twoor more of these HHV proteins involved in mediating HHV binding, fusion,and entry into host cells, such as gp350, gH, gL, and gB, producesadditive or synergistic antibody responses. These robust results areparticularly unexpected in view of the art-recognized problem of vaccineor immune interference, commonly observed when administering multipleantigens as part of a multi-component vaccine or a sequentialvaccination schedule. Without intending to be bound by any theory, itappears that the combination of two or more HHV polypeptides elicitshigh-titer, neutralizing antibody responses that block different stepsof the virus-host cell fusion process and, thus, provide improvedprotection against HHV infection in vivo.

Although strategies for multimerizing HHV proteins to enhanceimmunogenicity have recently been reported (see e.g., WO2014/018858 andWO2015/089340), we have discovered that unexpected additive andsynergistic antibody responses can be obtained by combining monomeric ormultimeric forms of the HHV fusion and host cell entry protein. Thus, incertain embodiments, one or more of the HHV fusion and host cell entryproteins is monomeric and/or multimeric. The HHV fusion and host cellentry proteins can be recombinant proteins or native proteins. Incertain embodiments, the HHV fusion and host cell entry proteins havebeen modified and are not naturally occurring proteins. For example, theproteins may be truncated, multimerized, or combined in a fusionprotein.

Although typically administered as polypeptides, it is also possible toadminister nucleic acids encoding the HHV fusion and host cell entryproteins as a DNA vaccine, an RNA vaccine, or a viral vector vaccine. Itis also possible to administer virus-like particles that express the HHVfusion and host cell entry proteins.

The present disclosure also discloses for the first time that high titeranti-HHV antibodies, such as antibodies generated in response to the HHVprotein combinations disclosed herein, can passively transfer immunityand protect against HHV infection. This aspect covers methods ofidentifying biological samples that contain high titer anti-HHVantibodies and collecting antibodies and/or immune cells fromindividuals that are highly seropositive for HHV antigens, and/orindividuals who have been administered the antigenic compositionsdisclosed herein, and administering those antibodies and/or immune cellsto a subject in need thereof, thereby passively transferring immunity tothe subject and protecting the subject from HHV infection, particularlyin individuals who are immunocompromised or otherwise at risk ofdeveloping an HHV infection.

In a first aspect, the present disclosure provides antigeniccompositions that include at least two of the following antigenic humanherpesvirus polypeptides (or one or more nucleic acids encoding thesame): a glycoprotein B (gB) polypeptide comprising an extracellulardomain of human herpesvirus gB; a glycoprotein 350 (gp350) polypeptidecomprising an extracellular domain of human herpesvirus gp350; aglycoprotein L (gL) polypeptide; and a glycoprotein H (gH) polypeptidecomprising an extracellular domain of human herpesvirus gH. Suchcompositions may optionally include adjuvants and/or excipients commonin the field of vaccine development.

The human herpes virus from which the polypeptides are obtained can behuman cytomegalovirus (HCMV), Herpes Simplex Virus-1 (HSV-1), HerpesSimplex Virus-2 (HSV-2), Varicella-Zoster Virus (VZV), Epstein-BarrVirus (EBV), Human Herpes Virus 6 (HHV 6), Human Herpes Virus 7 (HHV 7),and/or Kaposi Sarcoma-related Herpes Virus (HSHV). In one embodiment,the polypeptides are EBV polypeptides.

In certain embodiments, the gB polypeptide, the gp350 polypeptide, thegL polypeptide, and/or the gH polypeptide, when present in the antigeniccomposition, each further comprises a corresponding intracellulardomain. The extracellular domain of the selected polypeptides can befused to the intracellular domain via a polypeptide linker sequence ofabout 6 to about 70 amino acids in length, or in particular about 15amino acids in length, for example. In other embodiments, at least two,or optionally three, of the human herpesvirus polypeptides form a fusionprotein, wherein the fusion protein optionally comprises a polypeptidelinker sequence that covalently links the polypeptides.

In a further embodiment, the antigenic composition includes the gBpolypeptide and one or more of the gp350, gL, and gH polypeptides. Invarious embodiments mentioned herein, the gB polypeptide can bemonomeric or multimeric (e.g., dimeric, trimeric, tetrameric, etc.). Incertain embodiments, the antigenic composition comprises the gBpolypeptide, the gH polypeptide, and the gL polypeptide. The gL and gHpolypeptides can optionally be present as a heterodimer. In certainembodiments, the heterodimer is a fusion protein. In other embodiments,the heterodimer is a non-covalently associated protein complex. In oneembodiment, the gB polypeptide is monomeric, dimeric, or trimeric andthe gL and gH polypeptides form a heterodimer. In another embodiment,the gB polypeptide is monomeric and the gL and gH polypeptides form amonomeric heterodimer.

In HCMV embodiments of the antigenic compositions, at least thefollowing combinations are contemplated: gB polypeptide, the gHpolypeptide, and the gL polypeptide. In one embodiment, the gBpolypeptide is monomeric, dimeric, or trimeric and the gL and gHpolypeptides form a heterodimer, which can be monomeric or multimeric(e.g., monomeric, dimeric, trimeric, or tetrameric). In anotherembodiment, the gB polypeptide is monomeric or trimeric and the gL andgH polypeptides form a monomeric or trimeric heterodimer. Theseantigenic compositions can further include a HCMV glycoprotein O (gO)polypeptide or an HCMV unique long 128 (UL128) polypeptide, an HCMVunique long 130 (UL130) polypeptide, and an HCMV unique long 131A(UL131A) polypeptide, and optionally an HCMV glycoprotein M polypeptide,and/or an HCMV glycoprotein N polypeptide.

In EBV embodiments of the antigenic compositions, at least the followingcombinations are contemplated: (a) the gp350 polypeptide and the gBpolypeptide, wherein the gp350 polypeptide is monomeric or tetramericgp350, and wherein the gB polypeptide is trimeric gB; (b) the gp350polypeptide, the gH polypeptide, and the gL polypeptide, where (i) thepolypeptides are monomeric, or (ii) the gp350 polypeptide is tetrameric,and the gH and gL polypeptides are trimeric; (c) the gB polypeptide, thegH polypeptide, and the gL polypeptide, where the gB polypeptide istrimeric gB, and where the gH polypeptide and gL polypeptide are bothmonomeric or trimeric; and (d) monomeric gp350 polypeptide, monomeric gHpolypeptide and monomeric gL polypeptide, and trimeric gB polypeptide,where the gp350 polypeptide is tetrameric, the gH and gL polypeptidesare monomeric or trimeric, and the gB polypeptide is trimeric. EBVantigen compositions can also optionally include a human EBVglycoprotein 42 (gp42) polypeptide, BDLF2 polypeptide, and/or a humanEBV BamH1-M rightward reading frame 2 (BMRF-2) polypeptide.

In HSV-1 and/or HSV-2 embodiments of the antigenic compositions, atleast the following combinations are contemplated: the gH polypeptide,the gL polypeptide, and the gB polypeptide, wherein each polypeptide ismonomeric or multimeric and optionally wherein the gH and gLpolypeptides form a gH/gL heterodimer. In certain embodiments, the gH/gLheterodimer is monomeric, dimeric, trimeric, or tetrameric and the gBpolypeptide is monomeric, dimeric, or trimeric. In one embodiment, thecombination comprises a monomeric or trimeric gH/gL heterodimer and amonomeric or trimeric gB polypeptide. These antigenic compositions canalso optionally include an HSV-1 or HSV-2 glycoprotein D (gD)polypeptide, in monomeric, dimeric, trimeric, or tetrameric form.

In VZV embodiments of the antigenic compositions, at least the followingcombinations are contemplated: the gH polypeptide, the gL polypeptide,and the gB polypeptide, wherein each polypeptide is monomeric ormultimeric and optionally wherein the gH and gL polypeptides form agH/gL heterodimer. In certain embodiments, the gH/gL heterodimer ismonomeric, dimeric, trimeric, or tetrameric and the gB polypeptide ismonomeric, dimeric, or trimeric. In one embodiment, the combinationcomprises a monomeric or trimeric gH/gL heterodimer and a monomeric ortrimeric gB polypeptide. These antigenic compositions can alsooptionally include one or more of a human VZV glycoprotein C (gC)polypeptide, human VZV glycoprotein E (gE) polypeptide, and/or human VZVglycoprotein I (gI) polypeptide.

In HHV-6 or HHV-7 embodiments of the antigenic compositions at least thefollowing combinations are contemplated: the gH polypeptide, the gLpolypeptide, and the gB polypeptide, wherein each polypeptide ismonomeric or multimeric and optionally wherein the gH and gLpolypeptides form a gH/gL heterodimer. In certain embodiments whereinthe gH/gL heterodimer is monomeric, dimeric, trimeric, or tetrameric andthe gB polypeptide is monomeric, dimeric, or trimeric. In oneembodiment, the combination comprises a monomeric or trimeric gH/gLheterodimer and a monomeric or trimeric gB polypeptide.

In KSHV embodiments of the antigenic compositions, at least thefollowing combinations are contemplated: the gH polypeptide, the gLpolypeptide, and the gB polypeptide, wherein each polypeptide ismonomeric or multimeric and optionally wherein the gH and gLpolypeptides form a gH/gL heterodimer. In certain embodiments, the gH/gLheterodimer is monomeric, dimeric, trimeric, or tetrameric and the gBpolypeptide is monomeric, dimeric, or trimeric. In one embodiment, thecombination comprises a monomeric or trimeric gH/gL heterodimer and amonomeric or trimeric gB polypeptide. These antigenic compositions canalso optionally include one or more of a human KSHV glycoprotein M (gM)polypeptide, a human KSHV glycoprotein N (gN) polypeptide, a human KSHVOpen Reading Frame 68 (ORF68) polypeptide, and/or a human KSHV K8.1polypeptide.

In antigenic compositions comprising nucleic acids, the nucleic acidscan be in a viral vector that permits expression of the humanherpesvirus polypeptides.

Also provided are methods for preventing or treating a human herpesvirusinfection in a subject by administering a therapeutically effectiveamount of two or more of the HHV polypeptides that comprise thedisclosed antigen compositions. Further, provided are methods forinducing immunity to a human herpesvirus in a subject by administering atherapeutically effective amount of two or more of the HHV fusion andhost cell entry proteins that comprise one or more of the disclosedantigenic compositions. The two or more HHV fusion and host cell entryproteins may be administered simultaneously or separately.

The treated subjects can be those who are at risk of developingpost-transplantation lymphoproliferative disorder (PTLD) followinghematopoietic stem cell or solid organ transplantation and/or thosesuffering from a primary immunodeficiency syndrome. In the disclosedmethods, the antigenic compositions can be administered sequentially orconcurrently.

Recombinant nucleic acid constructs for expressing the HHV polypeptidesor protein complexes are also disclosed, as well as their correspondingencoded polypeptides.

In one embodiment, the recombinant nucleic acid construct includes afirst nucleic acid molecule encoding a HHV gL polypeptide, a secondnucleic acid molecule encoding a HHV gH polypeptide, a third nucleicacid molecule encoding a HHV UL128 polypeptide, a fourth nucleic acidmolecule encoding a HHV UL130 polypeptide, and a fifth nucleic acidmolecule encoding a HHV UL131A polypeptide. In certain embodiments, apentameric gH/gL/UL128/UL130/UL131A protein complex is formed when thepolypeptides are expressed from the nucleic acid construct in a hostcell. The polypeptides optionally do not include a transmembrane domainand/or an intracellular domain. In one embodiment, the recombinantnucleic acid construct further includes a first promoter operativelylinked to the first nucleic acid and a second promoter operativelylinked to the third nucleic acid molecule. The nucleic acid constructoptionally also includes a first internal ribosome entry site (IRES)located between the first nucleic acid molecule and the second nucleicacid molecule, a second IRES located between the third nucleic acidmolecule and the fourth nucleic acid molecule, and a third IRES locatedbetween the fourth nucleic acid molecule and the fifth nucleic acidmolecule. Optionally, the nucleic acid construct also includes a first,second, third, fourth, and fifth nucleotide sequence encoding an IgGkappa light chain leader peptide, wherein the first, second, third,fourth, and fifth nucleotide sequence encoding the IgG kappa light chainleader peptide is in frame with the first, second, third, fourth, andfifth nucleic acid molecules, respectively. In certain embodiments, theHHV is HCMV, EBV, HSV-1, HSV-2, VZV, KSHV.

In another embodiment, the recombinant nucleic acid construct includes afirst nucleic acid molecule encoding a HHV gL polypeptide, a secondnucleic acid molecule encoding a HHV gH polypeptide, and a third nucleicacid molecule encoding a HHV gO polypeptide. In certain embodiments, atrimeric gL/gH/gO protein complex is formed when the polypeptides areexpressed from the nucleic acid construct in a host cell. In certainembodiments, the HHV is HCMV, EBV, HSV-1, HSV-2, VZV, or KSHV.

Methods of passively transferring immunity against Epstein-Barr virus(EBV) are also disclosed. These methods are achieved by administering toa subject in need thereof immune cells or high titer anti-EBVimmunoglobulins, wherein the immune cells or high titer anti-EBVimmunoglobulins have been obtained from one or more blood, plasma, orserum samples, optionally human blood, plasma, or serum samples, thathave been selected for the high titer anti-EBV immunoglobulins. In theseembodiments, the titer of the high titer anti-EBV immunoglobulins can beup to 25-fold, 4- to 25-fold, or 10- to 20-fold, higher than the averagetiter of anti-EBV immunoglobulins obtained from unselected blood,plasma, or serum samples. The blood, plasma, or serum samples can beobtained from a donor who was immunized with two or more EBV fusion andhost cell entry proteins. The blood, plasma, or serum samples can alsobe obtained from a donor who was immunized with a single multimeric EBVprotein involved in mediating EBV binding, fusion, and entry into hostcells, including but not limited to, tetrameric gp350, trimeric gH/gL,or trimeric gB. Subjects in need thereof can be subjects that are atrisk of developing post-transplantation lymphoproliferative disorder(PTLD) following hematopoietic stem cell or solid organ transplantation,or that have or are at risk of developing nasopharyngeal carcinoma(NPC), Burkitt lymphoma, Hodgkin's lymphoma, non-Hodgkin's lymphoma,gastric carcinoma, severe infectious mononucleosis, chronic active EBVinfection, multiple sclerosis, systemic lupus erythematosus, orrheumatoid arthritis. In certain embodiments, the subject isseronegative for EBV.

In one embodiment, the method of passively transferring immunity againstEBV is performed on a subject that is concurrently receiving one or moreof anti-CD20 antibody administration, anti-viral therapy, interferonalpha administration, radiotherapy, and chemotherapy.

In another embodiment of the passive transfer method, the methodincludes one or more of the following steps: (i) identifying a blood,plasma, or serum sample obtained from one or more human subjects thatcontain high EBV neutralizing activity; and/or (ii) collecting hightiter anti-EBV immunoglobulins from the blood, plasma or serum samplecontaining high EBV neutralizing activity. In this embodiment andrelated method embodiments, the identifying step optionally includessubjecting the blood, plasma, or serum sample to a Raji B cellneutralization assay and/or a HeLa cell neutralization assay. In thisembodiment, the HeLa cell neutralization assay includes the steps ofinfecting HeLa cells with GFP labeled EBV to yield EBV-infected HeLacells, incubating the blood, plasma, or serum sample with theEBV-infected HeLa cells, analyzing the neutralization activity of theblood, plasma, or serum sample with flow cytometry or ELISpot assay andoptionally calculating the IC₅₀ of the blood, plasma, or serum sample.Also in this embodiment, the blood, plasma, or serum sample isidentified as containing high EBV neutralizing activity if the blood,plasma, or serum sample has an IC₅₀ that is 4- to 25-fold, or 10- to20-fold, higher than the average IC₅₀ of unselected blood, plasma orserum samples.

In another embodiment of the passive transfer method, the methodincludes administering to one or more human donor subjects at least twoof the following EBV polypeptides: an EBV gp350 polypeptide, an EBVgH/gL heterodimer comprising an EBV gH polypeptide and an EBV gLpolypeptide, and an EBV gB polypeptide, in an amount sufficient togenerate high titer anti-EBV immunoglobulin, and collecting the hightiter anti-EBV immunoglobulins from the one or more human donor subjectsbefore the step of administering to the subject the high titer anti-EBVimmunoglobulins. In certain embodiments, the EBV gp350 polypeptide ismonomeric, dimeric, trimeric, or tetrameric, the EBV gB polypeptide ismonomeric, dimeric, or trimeric, and the gH/gL heterodimer is monomeric,dimeric, trimeric, or tetrameric.

In a further embodiment, methods are provided for passively transferringimmunity against human cytomegalovirus (HCMV). The methods include thestep of administering to a subject in need thereof immune cells or hightiter anti-HCMV immunoglobulins, where the immune cells or high titeranti-HCMV immunoglobulins have been obtained from one or more blood,plasma, or serum samples, optionally human blood, plasma, or serumsamples, that have been selected for the high titer anti-HCMVimmunoglobulins. Optionally, the blood, plasma or serum samples havebeen obtained from a donor who was immunized with two or more HCMVfusion and host cell entry proteins. The blood, plasma, or serum samplescan also be obtained from a donor who was immunized with a singlemultimeric HCMV protein involved in mediating HCMV binding, fusion, andentry into host cells, including but not limited to, trimeric gH/gL ortrimeric gB. In one embodiment of this passive transfer method, thesubject is at risk of contracting HCMV infection is a pregnant woman, atransplantation patient, a patient who is immunosuppressed duringchemotherapy or radiotherapy, or a patient infected with humanimmunodeficiency virus (HIV).

In another embodiment of the HCMV passive transfer method, the methodalso includes one or more of the following steps performed before thestep of administering to the subject the high titer anti-HCMVimmunoglobulins: (i) administering to one or more human donor subjectsat least two of an HCMV gB polypeptide, an HCMV gH/gL heterodimercomprising an HCMV gH polypeptide and an HCMV gL polypeptide, an HCMVglycoprotein O (gO) polypeptide, an HCMV UL128 polypeptide, an HCMVUL130 polypeptide, and an HCMV unique UL131A polypeptide, in an amountsufficient to generate a high titer anti-HCMV immunoglobulin response inthe subject; and (ii) collecting the high titer anti-HCMVimmunoglobulins from the one or more human donor subjects. In certainembodiments, the HCMV gB polypeptide is monomeric, dimeric, or trimeric,and the gH/gL heterodimer is monomeric, dimeric, trimeric, ortetrameric.

Also disclosed are methods of passively transferring immunity againstHerpes Simplex Virus Type 1 (HSV-1) or Herpes Simplex Virus Type 2(HSV-2). These methods achieve passive transfer by administering to asubject in need thereof immune cells or high titer anti-HSV-1 and/oranti-HSV-2 immunoglobulins, wherein the immune cells or high titeranti-HSV-1 or anti-HSV-2 immunoglobulins have been obtained from one ormore blood, plasma, or serum samples, optionally human blood, plasma, orserum samples, that have been selected for the high titer anti-HSV-1 oranti-HSV-2 immunoglobulins. Optionally, the blood, plasma or serumsamples have been obtained from a donor who was immunized with two ormore HSV-1 or HSV-2 fusion and host cell entry proteins. The blood,plasma, or serum samples can also be obtained from a donor who wasimmunized with a single multimeric HSV-1 or HSV-2 protein involved inmediating HSV-1 or HSV-2 binding, fusion, and entry into host cells,including but not limited to, trimeric gH/gL or trimeric gB. In anotherembodiment of this method, the subject is at risk of developingencephalitis caused by HSV-1 or HSV-2 infection, or wherein the subjectis a pregnant woman with active HSV-2 or HSV-1 infection and/or HSVencephalitis.

In another embodiment of the HSV-2 or HSV-1 passive transfer method, themethod also includes one or more of the following steps performed beforethe step of administering to the subject the high titer anti-HSV-2 orHSV-1 immunoglobulins: (i) administering to one or more human donorsubjects at least two of an HSV-1 or HSV-2 glycoprotein D (gD)polypeptide, an HSV-1 or HSV-2 gH/gL heterodimer comprising an HSV-1 orHSV-2 gH polypeptide and an HSV-1 or HSV-2 gL polypeptide, an HSV-1 orHSV-2 gB polypeptide, in an amount sufficient to generate high titeranti-HSV-1 or HSV-2 immunoglobulins; and/or (ii) collecting the hightiter anti-HSV-1 and/or anti-HSV-2 immunoglobulins from the one or morehuman donor subjects. In certain embodiments, the HSV-1 or HSV-2 gBpolypeptide is monomeric, dimeric, or trimeric, and the HSV-1 or HSV-2gH/gL heterodimer is monomeric, dimeric, trimeric or tetrameric.

Also disclosed are methods of passively transferring immunity againstVZV. These methods achieve passive transfer by administering to asubject in need thereof immune cells or high titer anti-VZVimmunoglobulins, wherein the immune cells or high titer anti-VZVimmunoglobulins have been obtained from one or more blood, plasma, orserum samples, optionally human blood, plasma, or serum samples, thathave been selected for the high titer anti-VZV immunoglobulins.Optionally, the blood, plasma or serum samples have been obtained from adonor who was immunized with two or more VZV fusion and host cell entryproteins. The blood, plasma, or serum samples can also be obtained froma donor who was immunized with a single multimeric VZV protein involvedin mediating VZV binding, fusion, and entry into host cells, includingbut not limited to, trimeric gH/gL or trimeric gB. In another embodimentof this method, the subject is at risk of developing Zoster (shingles)or Varicella (chickenpox).

In another embodiment of the VZV passive transfer method, the methodalso includes one or more of the following steps performed before thestep of administering to the subject the high titer anti-VZVimmunoglobulins: (i) administering to one or more human donor subjectsat least two of a VZV gH/gL heterodimer comprising a VZV gH polypeptideand a VZV gL polypeptide, a VZV gB polypeptide, a VZV glycoprotein C(gC) polypeptide, a VZV glycoprotein E (gE) polypeptide, and a VZVglycoprotein I (gI) polypeptide, in an amount sufficient to generatehigh titer anti-VZV immunoglobulins; and/or (ii) collecting the hightiter anti-VZV immunoglobulins from the one or more human donorsubjects. In certain embodiments, the VZV gB polypeptide is monomeric,dimeric, or trimeric, and the VZV gH/gL heterodimer is monomeric,dimeric, trimeric, or tetrameric.

Also disclosed are methods of passively transferring immunity againsthuman herpesvirus 6 (HHV-6) or human herpesvirus 7 (HHV-7). Thesemethods achieve passive transfer by administering to a subject in needthereof immune cells or high titer anti-HHV-6 or anti-HHV-7immunoglobulins, wherein the immune cells or high titer anti-HHV-6 oranti-HHV-7 immunoglobulins have been obtained from one or more blood,plasma, or serum samples, optionally human blood, plasma, or serumsamples, that have been selected for the high titer anti-HHV-6 oranti-HHV-7 immunoglobulins. Optionally, the blood, plasma or serumsamples have been obtained from a donor who was immunized with two ormore HHV-6 or HHV-7 fusion and host cell entry proteins. The blood,plasma, or serum samples can also be obtained from a donor who wasimmunized with a single multimeric HHV-6 or HHV-7 protein involved inmediating HHV-6 or HHV-7 binding, fusion, and entry into host cells,including but not limited to, trimeric gH/gL or trimeric gB. In anotherembodiment of the HHV-6 or HHV-7 passive transfer method, the methodalso includes one or more of the following steps performed before thestep of administering to the subject the high titer anti-HHV-6 oranti-HHV-7 immunoglobulins: (i) administering to one or more human donorsubjects at least a HHV-6 or HHV-7 gH/gL heterodimer and a HHV-6 orHHV-7 gB polypeptide, in an amount sufficient to generate high titeranti-HHV-6 or anti-HHV-7 immunoglobulins; and/or (ii) collecting thehigh titer anti-HHV-6 or anti-HHV-7 immunoglobulins from the one or morehuman donor subjects. In certain embodiments, the HHV-6 or HHV-7 gBpolypeptide is monomeric, dimeric, or trimeric, and the gH/gLheterodimer is monomeric, dimeric, trimeric, or tetrameric,

Also disclosed are methods of passively transferring immunity againstKaposi's sarcoma herpesvirus (KSHV). These methods achieve passivetransfer by administering to a subject in need thereof immune cells orhigh titer anti-KSHV immunoglobulins, wherein the immune cells or hightiter anti-KSHV immunoglobulins have been obtained from one or moreblood, plasma, or serum samples, optionally human blood, plasma, orserum samples, that have been selected for the high titer anti-KSHVimmunoglobulins. Optionally, the blood, plasma or serum samples havebeen obtained from a donor who was immunized with two or more KSHVfusion and host cell entry proteins. The blood, plasma, or serum samplescan also be obtained from a donor who was immunized with a singlemultimeric KSHV protein involved in mediating KSHV binding, fusion, andentry into host cells, including but not limited to, trimeric gH/gL ortrimeric gB. In another embodiment of this method, the subject is atrisk of developing KSHV-associated Kaposi's sarcoma, primary effusionlymphoma, multicentric Cattleman's disease, KSHV-associated inflammatorycytokine syndrome, or KSHV immune reconstitution inflammatory syndrome.

In another embodiment of the KSHV passive transfer method, the methodalso includes one or more of the following steps performed before thestep of administering to the subject the high titer anti-KSHVimmunoglobulins: (i) administering to one or more human donor subjectsat least two of a KSHV gH/gL heterodimer comprising a KSHV gHpolypeptide and a KSHV gL polypeptide, a KSHV gB polypeptide, a KSHV gMpolypeptide, a KSHV gN polypeptide, a KSHV ORF68 polypeptide, and a KSHVK8.1 polypeptide, in an amount sufficient to generate high titeranti-KSHV immunoglobulins; and/or (ii) collecting the high titeranti-KSHV immunoglobulins from the one or more human donor subjects. Incertain embodiments, the KSHV gB polypeptide is monomeric, dimeric, ortrimeric, and the gH/gL heterodimer is monomeric, dimeric, trimeric, ortetrameric.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate certain embodiments, and togetherwith the written description, serve to explain certain principles of theconstructs and methods disclosed herein.

FIG. 1 shows a schematic of recombinant constructs for expressingnon-limiting embodiments of multimeric EBV gp350, gH/gL, and gB. FIG. 1discloses “(Gly₄Ser₁)3” as SEQ ID NO: 3, “His₆” as SEQ ID NO: 49, and“RRRRRD” as SEQ ID NO: 55.

FIGS. 2A-C show images of a Western blot of monomeric and multimeric EBVgH/gL (FIG. 2A), EBV gB (FIG. 2B), and EBV gp350 (FIG. 2C) polypeptides.

FIG. 3 shows EBV in vitro neutralization analysis of the sera fromrabbits immunized with gp350 monomer (left panel, open circles), gp350tetramer (left panel, closed circles), gB trimer (right panel), gH/gLmonomer (middle panel, open circles), and gH/gL trimer (middle panel,closed circles).

FIGS. 4A-B show neutralization titers of serum from rabbits immunizedwith monomeric or tetrameric EBV gp350, monomeric or trimeric EBV gH/gL,or trimeric EBV gB in alum+CpG-ODN adjuvant in either Raji cells (FIG.4A) or naïve peripheral blood human B cells (FIG. 4B).

FIG. 5 shows EBV neutralization activity of immune sera from rabbitsimmunized with trimeric EBV gB or monomeric EBV gH/gL or the synergisticcombination of trimeric EBV gB and monomeric EBV gH/gL.

FIGS. 6A-B show EBV neutralization activity of pooled immune sera fromrabbits (n=5) immunized with tetrameric EBV gp350, trimeric EBV gB,trimeric EBV gH/gL, or combinations thereof (FIG. 6A) demonstratingsynergism, or with monomeric EBV gp350, trimeric EBV gB, monomeric EBVgH/gL, or synergistic combinations thereof (FIG. 6B).

FIGS. 7A-C show that passive transfer of immune rabbit sera prior toEBV-infection of humanized mice decreased EBV DNA load and increasedsurvival rate of challenged mice. FIG. 7A shows survival rate of miceexposed to high-dose, live EBV infection after passive transfer of serafrom rabbits immunized with tetrameric EBV gp350, trimeric EBV gH/gL,trimeric EBV gB, or adjuvant alone (control). FIG. 7B shows pooledimmune sera from rabbits immunized with tetrameric EBV gp350 or trimericEBV gH/gL decreased the copy number of EBV DNA in multiple organs ofthree humanized mice (geometric mean). FIG. 7C shows pooled immune serafrom rabbits immunized with tetrameric EBV gp350, trimeric EBV gH/gL ortrimeric EBV gB markedly decreased the EBV viral load in peripheralblood (geometric mean of 3 mice) compared to the control.

FIG. 8 shows a schematic of a wild type HCMV gB polypeptide and arecombinant construct for expressing a non-limiting embodiment of atrimeric HCMV gB polypeptide. FIG. 8 discloses “GGGGSGGGGSGGGGS” as SEQID NO: 3, “His₆” as SEQ ID NO: 49, and “RTKRS” as SEQ ID NO: 53.

FIGS. 9A-E show images of a Western blot of monomeric HCMV gB (FIG. 9A),trimeric HCMV gB (FIG. 9B), monomeric HCMV gH/gL (FIG. 9C), trimericHCMV gH/gL (FIG. 9D), and monomeric HCMV UL128/130/131A (FIG. 9E).

FIG. 10 shows a schematic representing a non-limiting cloning strategyfor expressing recombinant trimeric UL128/130/131A. FIG. 10 discloses“(Gly₄Ser)₃” as SEQ ID NO: 3 and “His₆” as SEQ ID NO: 49.

FIG. 11 shows the serum IgG titers of anti-gH/gL antibodies (left panel)and anti-gB antibodies (right panel) following immunization of rabbitswith monomeric HCMV gH/gL, trimeric HCMV gB, trimeric HCMV gB+monomericHCMV gH/gL, or a complex of trimeric HCMV gB+monomeric HCMV gH/gL.

FIG. 12A shows in vitro HCMV neutralization titers (IC₅₀) of non-heatinactivated serum from rabbits immunized with monomeric HCMV gH/gL, HCMVUL128/UL130/UL131A, monomeric HCMV gB (Sino gB), trimeric gB, or certainsynergistic combinations thereof using the ARPE19 epithelial cell line.

FIG. 12B shows in vitro HCMV neutralization titers (IC₅₀) ofheat-inactivated serum from rabbits immunized with monomeric HCMV gB(Sino gB), trimeric HCMV gB, monomeric HCMV gH/gL, or a synergisticcombination of trimeric HCMV gB and monomeric HCMV gH/gL using the MRC-5fibroblast cell line.

FIG. 13 shows a schematic diagram of a non-limiting DNA construct forexpression of the pentameric complex gH/gL/UL128/UL130/UL131A.

FIG. 14 shows a schematic diagram of a non-limiting DNA construct forexpression of a gH/gL/gO complex.

FIG. 15 shows in vitro HCMV neutralization activity of pooled immunesera from rabbits immunized with monomeric HCMV gB.

FIG. 16 shows in vitro HCMV neutralization activity of pooled immunesera from rabbits immunized with trimeric HCMV gB.

FIG. 17 shows in vitro HCMV neutralization activity of pooled immunesera from rabbits immunized with monomeric HCMV gH/gL.

FIG. 18 shows in vitro HCMV neutralization activity of in vitro combinedimmune sera from rabbits immunized with monomeric HCMV gB and monomericHMCV gH/gL.

FIG. 19 shows in vitro HCMV neutralization activity of in vitro combinedimmune sera from rabbits immunized with trimeric HCMV gB and monomericHMCV gH/gL.

FIG. 20 compares the in vitro HCMV neutralization activity of pooledimmune sera from rabbits immunized with individual HCMV proteins(monomeric gB, trimeric gB, and monomeric gH/gL) or in vitrocombinations of sera from rabbits immunized with HCMV proteins(monomeric gB and monomeric gH/gL or trimeric gB and monomeric gH/gL)and shows that the combination of HCMV proteins exhibit synergy.

FIG. 21A shows mouse serum titers of gB-specific IgG from mice immunizedwith different amounts of HCMV trimeric gB or HCMV monomeric gB.

FIGS. 21B-C show neutralization titers (IC₅₀) of heat-inactivated serum(FIG. 21B) or non-heat inactivated-serum (FIG. 21C) from mice immunizedwith monomeric HCMV gB or trimeric HCMV gB at various amounts (1 μg, 5μg, and 25 μg) or CytoGam® IVIg at 10 mg/mL as a control (CSL Behring,King of Prussia, Pa., USA).

DETAILED DESCRIPTION

It is to be understood that the following detailed description isprovided to give the reader a fuller understanding of certainembodiments, features, and details of aspects of the invention, andshould not be interpreted as a limitation of the scope of the invention.

Definitions

In order that the present invention may be more readily understood,certain terms are first defined. Additional definitions are set forththroughout the detailed description.

The term “antibody” as used in this disclosure refers to animmunoglobulin or an antigen-binding fragment thereof. The term includesbut is not limited to polyclonal, monoclonal, monospecific,polyspecific, non-specific, humanized, human, single-chain, chimeric,synthetic, recombinant, hybrid, mutated, grafted, and in vitro generatedantibodies. The antibody can include a constant region, or a portionthereof, such as the kappa, lambda, alpha, gamma, delta, epsilon and muconstant region genes. For example, heavy chain constant regions of thevarious isotypes can be used, including: IgG₁, IgG₂, IgG₃, IgG₄, IgM,IgA₁, IgA₂, IgD, and IgE. By way of example, the light chain constantregion can be kappa or lambda.

The terms “antigen-binding domain” and “antigen-binding fragment” referto a part of an antibody molecule that comprises amino acids responsiblefor the specific binding between the antibody and antigen. For certainantigens, the antigen-binding domain or antigen-binding fragment mayonly bind to a part of the antigen. The part of the antigen that isspecifically recognized and bound by the antibody is referred to as the“epitope” or “antigenic determinant” Antigen-binding domains andantigen-binding fragments include Fab (Fragment antigen-binding); aF(ab′)₂ fragment, a bivalent fragment having two Fab fragments linked bya disulfide bridge at the hinge region; Fv fragment; a single chain Fvfragment (scFv) see e.g., Bird et al. (1988) Science 242:423-426; andHuston et al. (1988) Proc. Natl. Acad. Sci. USA 85:5879-5883); a Fdfragment having the two V_(H) and C_(H)1 domains; dAb (Ward et al.,(1989) Nature 341:544-546), and other antibody fragments that retainantigen-binding function. The Fab fragment has V_(H)-C_(H)1 andV_(L)-C_(L) domains covalently linked by a disulfide bond between theconstant regions. The F_(v) fragment is smaller and has V_(H) and V_(L)domains non-covalently linked. To overcome the tendency ofnon-covalently linked domains to dissociate, a scF_(v) can beconstructed. The scF_(v) contains a flexible polypeptide that links (1)the C-terminus of V_(H) to the N-terminus of V_(L), or (2) theC-terminus of V_(L) to the N-terminus of V_(H). A 15-mer (Gly₄Ser)₃peptide (SEQ ID NO:3) may be used as a linker, but other linkers areknown in the art. These antibody fragments are obtained usingconventional techniques known to those with skill in the art, and thefragments are evaluated for function in the same manner as are intactantibodies.

As used in this application, “antigen” means a protein or fragmentthereof or a polysaccharide linked to a protein carrier that, whenexpressed in an animal or human cell or tissue, is capable of triggeringan immune response. The protein or fragment thereof may be glycosylatedor non-glycosylated.

The term “extracellular domain” means refers to the portion of a fulllength polypeptide that extends beyond the cellular membrane and intothe media in which the cell harboring the polypeptide resides.Polypeptides are known to generally contain an intracellular domain,transmembrane domain, and the remaining is the extracellular domain(“ECD”). When the term “extracellular domain” or “ECD” is used herein,it refers to the amino acids of a polypeptide that in wild type formextend beyond the cellular membrane, or any portion thereof recognizableby an antibody. Thus, the extracellular domain includes the entiredomain, or any number of residues amenable to recombinant expression andinclusion in an antigenic composition, including polypeptidesrepresenting 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% of theentire wild type extracellular domain of a polypeptide. That is, theextracellular domain may be shortened, or truncated, by known methods inthe art, to remove extraneous domains, on either the carboxy-terminus oramino-terminus end, or both, of the polypeptide as needed to obtain moreefficient and robust expression of the extracellular domain of thepolypeptide.

The term “full length” with respect to a given polypeptide means theform of the polypeptide naturally translated from the coding DNAsequence, beginning with the ATG start codon, which encodes the firstmethionine in the amino acid sequence, and ending at the TGA, TAG, orTTA stop codon, or whichever stop codon employed by the organism.

The term “fusion protein” refers to a protein translated from a nucleicacid transcript generated by combining a first nucleic acid sequencethat encodes a first protein and at least a second nucleic acid thatencodes a second protein, where the fusion protein is not a naturallyoccurring protein. The nucleic acid construct may encode two or moreproteins that are joined in the fusion protein to create a singlepolypeptide chain. The two or more nucleic acid sequences are optionallyoperatively linked to a single promoter, or operatively linked to two ormore separate promoters.

The term “glycoprotein” means a polypeptide that has covalently attachedto it one or more carbohydrate moieties, or oligosaccharide chains. Thecarbohydrate moieties are normally attached to glycoproteinsco-translationally or as post-translational modifications.

The term “isolated,” when used in the context of a polypeptide ornucleic acid refers to a polypeptide or nucleic acid that issubstantially free of its natural environment and is thusdistinguishable from a polypeptide or nucleic acid that might happen tooccur naturally. For instance, an isolated polypeptide or nucleic acidis substantially free of cellular material or other polypeptides ornucleic acids from the cell or tissue source from which it was derived.The term also refers to preparations where the isolated polypeptide ornucleic acid is sufficiently pure for pharmaceutical compositions; or atleast 70-80% (w/w) pure; or at least 80-90% (w/w) pure; or at least90-95% pure; or at least 95%, 96%, 97%, 98%, 99%, or 100% (w/w) pure.

The term “leader sequence” refers to a short peptide sequence at theN-terminus of a recombinant protein that directs the recombinant proteinto be secreted from a host cell.

The term “HHV fusion and host cell entry protein” refers to a humanherpesvirus gB polypeptide, gH polypeptide, gL polypeptide, gH/gLheterodimer, or gp350 polypeptide.

The term “HHV accessory protein” refers to a human herpes viruspolypeptide other than gB, gH, gL, gH/gL, or gp350 that are involved inmediating viral binding, fusion, and host cell entry including, but notlimited to, gp42, gM, gN, gI, gC, gD, ORF68, BMRF-2, BDLF2, UL128,UL130, UL131A, and gpK8.1.

The term “immune cell” means any cell of hematopoietic lineage involvedin regulating an immune response against an antigen (e.g., anautoantigen). In typical embodiments, an immune cell is a leukocyte,such as a white blood cell Immune cells include neutrophils,eosinophils, basophils, lymphocytes, and/or monocytes. Lymphocytesinclude T lymphocytes and B lymphocytes. Immune cells can also bedendritic cells, natural killer (NK) cells, and/or a mast cell.

The term “intracellular domain” means the portion of a polypeptide thatresides in the cytoplasm of a host cell. The intracellular domainincludes that portion of the polypeptide that is not the transmembranedomain and is not the extracellular domain.

The term “gH/gL heterodimer” refers to a polypeptide or polypeptidecomplex comprising a HHV gH polypeptide and a HHV gL polypeptide. Forexample, the heterodimer can be a non-covalently associated complexbetween a HHV gH polypeptide and a HHV gL polypeptide. Alternatively,the heterodimer can be a recombinant fusion protein comprising a HHV gHprotein joined to a HHV gL protein. The HHV gH protein can be joined tothe HHV gL protein with a peptide linker.

As used herein, the term “modified gB polypeptide,” refers to a HHV gBpolypeptide in which the furin cleavage site in the extracellular domainof the gB polypeptide is replaced by a linker sequence, as described inWO 2015/089340.

The term “operatively linked” means that a promoter, or similarregulatory element, is positioned next to an expressible nucleotidesequence or coding region such that the transcription of that codingregion is controlled and regulated by that promoter.

The terms “polypeptide,” “peptide,” and “protein” are usedinterchangeably herein to refer to polymers of amino acids.

The term “peptide linker” refers to a short, non-native peptide sequencethat links two proteins or fragments of a protein.

The term “recombinant” when used in the context of a nucleic acid meansa nucleic acid having nucleotide sequences that are not naturally joinedtogether and can be made by artificially combining two otherwiseseparated segments of sequence. This artificial combination is oftenaccomplished by chemical synthesis or, more commonly, by the artificialmanipulation of isolated segments of nucleic acids, for example, bygenetic engineering techniques. Recombinant nucleic acids includenucleic acid vectors comprising an amplified or assembled nucleic acid,which can be used to transform or transfect a suitable host cell. A hostcell that comprises the recombinant nucleic acid is referred to as a“recombinant host cell.” The gene is then expressed in the recombinanthost cell to produce a “recombinant polypeptide.” A recombinant nucleicacid can also serve a non-coding function (for example, promoter, originof replication, ribosome-binding site and the like).

The term “transmembrane domain” (or “TM”) means the portion of apolypeptide that naturally and completely traverses the cell membrane,which is a hydrophobic phospholipid bilayer that separates the cytoplasmfrom the external media in which the host cell resides. Transmembranedomains are typically between about 20 to about 25 amino acids inlength, depending on the polypeptide. The transmembrane is typicallylipophilic and therefore typically not included in antigeniccompositions disclosed herein because it is difficult to express, purifyand solubilize.

The term “pharmaceutically acceptable carrier” or “pharmaceuticallyacceptable excipient” means solvents, dispersion media, coatings,antibacterial agents and antifungal agents, isotonic agents, andabsorption delaying agents, and the like, that are compatible withpharmaceutical administration. The use of such media and agents forpharmaceutically active substances is well known in the art. In certainembodiments, the pharmaceutically acceptable carrier or excipient is notnaturally occurring.

The term “preventing” when used in the context of a disease or diseasecondition means prophylactic administration of a composition that stopsor otherwise delays the onset of a pathological hallmark or symptom of adisease or disorder.

The term “treating” when used in the context of a disease or diseasecondition means ameliorating, improving or remedying a disease,disorder, or symptom of a disease or condition associated with thedisease, or can mean completely or partially stopping, on a molecularlevel, the biochemical basis of the disease, such as halting replicationof a virus, etc.

The term “therapeutically effective amount” when used in the context ofan amount of an active agent means an amount that results in animprovement or remediation of the disease, disorder, or symptoms of thedisease or condition.

The term “passive transfer” or “passive immunotherapy” or “passiveimmunity” means obtaining antibodies and/or immune cells from a subjectexposed to an antigen and administering those antibodies and/or immunecells to a second subject, thereby providing the second subject withimmune protection against challenge with the antigen. Antibodies orimmune cells can be transferred in the form of blood, plasma, purifiedantibodies or immune cells, serum, etc. The second subject may beimmunocompromised and/or naïve (never exposed to the antigen). (See,Keller et al., Clin. Microbiol. Rev., 13(4):602-614, 2000).

Human Herpes Viruses. Herpesviridae are subdivided into threesubfamilies: alphaherpesvirus, betaherpesvirus, and gammaherpes, basedon biological properties and DNA genome similarities (Davison et al.,Antiviral Res., 56:1-11, 2002; MacDonald et al., Am. J. Cardiol.,64:359-362, 1989). (See Table 1; Willis et al., Br. Med. Bull.,62(1):125-138, 2002). The alphaherpesviruses include HHV-1, HHV-2, VZV,and pseudorabies virus (PRV), and are neurotropic, i.e., they tend toinfect or attack mainly the nervous system of hosts. Thealphaherpesvirus family has the broadest host range and spread rapidlyin a cell culture. Latent alphaherpesvirus infections are usuallyestablished in sensory neurons and lytic infection occurs in epidermalcells (Roizman B, Sears A E. Herpes simplex viruses and theirreplication. In: Fields B N, Knipe D M, Howley P M, eds. Fieldsvirology. Philadelphia: Lippincott-Raven, 1996:2231-95).

TABLE 1 Genome Sub- size (kb Site of latency Common name Designationfamily pairs) and persistence Herpes simplex Human herpes α 152 Neuronesvirus 1 virus 1 (sensory ganglia) Herpes simplex Human herpes α 152Neurones virus 2 virus 2 (sensory ganglia) Varicella zoster Human herpesα 125 Neurones virus virus 3 (sensory ganglia) Epstein-Barr Human herpesγ 172 B lymphocytes virus virus 4 (oropharyngeal epithelium) Human Humanherpes β 235 Blood monocytes cytomegalovirus virus 5 (probablyepithelial cells) Human herpes β 170 Monocytes, T virus 6 lymphocytesHuman herpes β 145 Monocytes, T virus 7 lymphocytes Kaposi's sarcomaHuman herpes γ 230 Uncertain associated herpes virus 8 virus

The betaherpesvirus subfamily consists of all cytomegalovirusesincluding human cytomegalovirus (HCMV, HHV-8), HHV-6, and HHV-7 and arecommonly referred to as the roseoloviruses. The betaherpesvirus familyhas a restricted host range and a long infection cycle. Virus latency ofbetaherpesvirus is maintained in secretory glands, kidneys and othertissues (Hendrix et al., Expert Rev. Anti Infect. Ther., 5:427-439,2007).

The gammaherpesvirus subfamily is divided into the Lymphocryptoviruses,which includes EBV, Rhadinovirus, and HHV-8 (KSHV). Gammaherpesviruseshave a very narrow host range, and virus replication typically occurs inlymphoblastoid cells but can also lytically infect epithelial cells andfibroblasts. The latent form of gammaherpes virus infection is primarilyobserved in B and T lymphocytes (Ackerman, Vet. Microbiol., 113:211-222,2006).

Gammaherpesviruses: Epstein Barr Virus (EBV, HHV-4), and Kaposi'sSarcoma Virus-Associated Herpes (KSHV, HHV-8)

Epstein Barr Virus (EBV, HHV-4). Epstein-Barr virus (EBV) is the firsthuman cancer virus discovered, and it is strongly implicated in theetiology of post-transplant lymphoproliferative disorder (PTLD) andundifferentiated nasopharyngeal carcinoma (NPC). In both instances, theonset and severity of disease is positively correlated with the level ofEBV viremia, strongly suggesting a role for lytic EBV re-activation inperpetuating disease. Epstein Barr virus (EBV), also known as humanherpesvirus 4 (HHV-4), is a major, global source of morbidity andmortality, responsible for such pathologic entities as Burkitt lymphoma,nasopharyngeal carcinoma, infectious mononucleosis, a subset ofHodgkin's disease, and the lymphoproliferative syndrome inimmunosuppressed patients. (Cohen J I, Curr. Opin. Immunol., 1999August; 11(4):365-70; Thorley-Lawson D A, J., Allergy Clin. Immunol.,2005 August; 116(2):251-61; quiz 62; and Vetsika E K, Callan M., ExpertRev. Mol. Med., 2004 Nov. 5; 6(23):1-16). EBV has a double stranded,linear DNA genome. The nucleotide sequence of the EBV genome and theamino acid sequences of the viral proteins encoded thereby are known andset forth under the NCBI Reference Number NC_009334, VersionNC_009334.1, GI:139424470, which sequences are hereby incorporated byreference.

EBV is a member of the gammaherpesvirus subfamily, which is furtherdivided into lymphocryptoviruses, of which KSHV (HHV-8) is also amember. Replication for these family members typically occurs inlymphoblastoid cells, however they can also infect epithelial cells(e.g., nasopharyngeal epithelial cells) and fibroblasts. Latentinfection is primarily observed in B and T lymphocytes. (Ackerman, Vet.Microbiol., 113:211-222, 2006).

Post-Transplant Lymphoproliferative Disease (PLTD). Patients undergoingsolid organ or stem cell transplantation are at risk of developingpost-transplantation lymphoproliferative disorder (PTLD), characterizedby uncontrolled EBV-driven B cell proliferation that can evolve intonon-Hodgkin lymphoma. (LaCasce, Oncologist, 11:674-80, 2006). PTLD mayarise from EBV reactivation in seropositive recipients, or from primaryEBV infection from the donor allograft, which poses even greater risk.(Dharnidharka et al., Am. J. Transplant, 12:976-83, 2012). A similarphenomenon also occurs in patients with AIDS.

Most cases of PTLD involve excessive EBV-driven proliferation of Bcells, with a minority (10-15%) of cases being of the NK cell/T celltype (Petrara et al., Cancer Lett., 369(1):37-44, 2015; and Starzl etal., Lancet, 1:583-7, 1984). The frequency of PTLD ranges from 1-20%depending on the type of transplant, age of recipient, duration and typeof immunosuppressive treatment (Ibrahim et al., Adv Hematol.,2012:230173, 2012; and Smets et al., Recent Results Cancer Res.,193:173-90, 2014). Younger patients, who are EBV seronegative, are athighest risk of developing PTLD following hematopoietic stem cell orsolid organ transplantation, due to a lack of prior immunity. Patientswith primary immunodeficiency syndromes are also at high risk fordeveloping EBV-driven B cell lymphoproliferation and lymphoma (Rickinsonet al., Trends Immunol., 35:159-69, 2014). The WHO defines three majorhistological types of PTLD of increasing severity: early lesions,polymorphic (P-PTLD), and monomorphic (M-PTLD) (Harris et al., Semin.Diagn. Pathol., 14:8-14, 1997), with the latter typically manifesting asnon-Hodgkin lymphoma.

The initial management of PTLD is a reduction in immunosuppression.Additional therapeutic options include B cell-depleting anti-CD20 mAbtreatment, anti-viral therapy, intravenous immunoglobulin (IVIg) andinterferon (IFN)-γ (LaCasce A S, Oncologist, 11:674-80, 2006). AlthoughIVIg in particular has been used empirically in combination with othertherapies to treat PTLD, there have been no studies assessing itspotential clinical benefit.

Nasopharyngeal carcinoma and EBV. The non-keratinizing variant ofsquamous cell carcinoma of the nasopharynx (NPC) is endemic in east andsoutheast Asia and in parts of north and east Africa, and in 2012accounted for 86,500 cases of cancer worldwide. (Chua et al., Lancet,387(10022):1012-1024, 2016). NPC manifests clinically as epistaxis,unilateral nasal obstruction, auditory complaints, and cranial nervepalsies, with frequent metastasis to cervical lymph nodes. Radiotherapyis the primary treatment for NPC, with additional chemotherapy utilizedfor more advanced cases. (Id.). 5-year survival is 70-98% depending uponthe stage, but NPC has a tendency to recur.

Undifferentiated NPC is invariably associated with EBV, which isbelieved to play a pathogenic role in tumor development and progression.(Tsang et al., Virol. Sin., 30:107-21, 2015). Establishment of latentEBV infection in pre-malignant nasopharyngeal epithelial cells appearsto drive further malignant transformation. Rising levels of serum IgAspecific for EBV lytic antigens such as viral capsid antigen and earlyantigen correlate with progression to NPC. (Ji et al., Br. J. Cancer,96:623-30, 2007). The level of plasma EBV DNA is directly correlatedwith NPC tumor burden. (To et al., Clin. Cancer Res., 9:3254-9, 2003).Thus, latent EBV reactivation is a key feature of NPC formation andprogression, suggesting a possible role for antibody-basedimmunotherapy. Although multiple strains of EBV can be isolated from theblood and saliva of healthy seropositive individuals, only a singlestrain of EBV is typically isolated from NPC cells, consistent with itspathogenic role. (Tsang et al., Virol. Sin., 30:107-21, 2015). Althoughstrain variations in the sequences of EBNA2, 3A, 3B, and 3C have beendescribed, the envelope proteins gp350, gH/gL, and gB are highlyconserved, making these latter proteins ideal vaccine candidates forcross-strain protection. (Sample et al., J. Virol., 64:4084-92, 1990;and Rowe et al., J. Virol., 63:1031-9, 1989).

Circulating EBV DNA copy number is positively correlated with imminentonset of EBV-associated malignancies and clinical severity. EBV qPCRassays are commonly used post-transplantation. (Meerbach et al., J. Med.Virol., 80:441-54, 2008; Tsai et al., Am. J. Transplant, 8:1016-24,2008; Wagner et al., Transplantation, 74:656-64, 2002; and van Esser etal., Blood 98:972-8, 2001). Elevated EBV DNA in the blood is associatedwith an increased risk for PTLD, whereas decreases correlate withtreatment success. (Baldanti et al., J. Clin. Microbiol., 38:613-9,2000; Hakim et al., J. Clin. Microbiol., 45:2151-5, 2007; Wagner et al.,Transplantation, 72:1012-9, 2001; and Clave et al., Transplantation,77:76-84, 2004). Circulating EBV DNA is also positively correlated withadverse survival outcomes in NPC (Jin et al., Eur. J. Cancer, 48:882-8,2012; Hsu et al., Head Neck, 34:1064-70, 2012; and Hsu et al., OralOncol., 49:620-5, 2013), as well as Hodgkin (Kanakry et al., Blood,121:3547-53, 2013) and extranodal NK/T cell lymphomas, which also linkedpathogenically with EBV (Wang et al., Oncotarget., 6(30):30317-30326,2015).

In the developing world, EBV seroconversion typically occurs in infancy,whereas in developed countries it is more likely contracted inadolescence. Infectious mononucleosis typically occurs only in thislatter group (Vetsika et al., Expert Rev. Mol. Med., 2004 Nov. 5;6(23):1-16). The major human reservoir for latent EBV and EBVtransmission is the resting memory B lymphocyte (Babcock et al.,Immunity, 1998 September; 9(3):395-404). EBV is dependent upon thegp350-CD21 binding event for viral entry into the B cell (Tanner et al.,Cell, 1987 Jul. 17; 50(2):203-13; and Tanner et al., J. Virology, 1988;62(12):4452-64), an event that is critical for infectivity and B cellneoplastic transformation (Thorley-Lawson D A, J. Allergy Clin.Immunol., 2005 August; 116(2):251-61; quiz 62). Gp350 is the major EBVouter membrane glycoprotein, while CD21, also known as complementreceptor type 2 (CR2), is a receptor on the surface of B cells thatbinds to iC3b complement protein. Sera from patients with active EBVinfection contain antibody that prevent EBV entry into B cells(“neutralizing” antibody). Adsorption of these sera with gp350,eliminates most of this neutralizing activity (Thorley-Lawson et al., J.Virology, 1982 August; 43(2):730-6), indicating that gp350 serves as themajor EBV antigen to which a protective humoral immune response isdirected.

A number of studies have demonstrated that immunization of non-humanprimates with a subunit gp350 vaccine in adjuvant protects againstexperimental EBV-induced lymphoma or EBV replication. Thus, purifiednative gp350, injected into cottontop marmosets (CTM), in associationwith liposomes, ISCOM's, or muramyl dipeptide, protected againstEBV-induced lymphoma. (Morgan et al., J. Med. Virol., 1984;13(3):281-92; and Morgan et al., J. Med. Virol., 1989 September;29(1):74-8). Recombinant gp350 in alum or muramyl dipeptide wassimilarly protective. (Finerty et al., J. Gen. Virol., 1992 February; 73(Pt 2):449-53; and Finerty et al., Vaccine, 1994 October;12(13):1180-4). Common marmosets also showed decreased viral replicationafter EBV challenge following immunization with recombinant gp350 inalum. (Cox et al., J. Med. Virol., 1998 August; 55(4):255-61). Non-humanprimate studies using gp350 expressed by adenoviral or vaccinia viralvectors have similarly shown protection against experimental EBV-inducedlymphoma or EBV replication in CTM or common marmosets. (Mackett et al.,J. Med. Virol., 1996 November; 50(3):263-71; Ragot et al., J. Gen.Virol., 1993 March; 74 (Pt 3):501-7; and Morgan et al., J. Med. Virol.,1988 June; 25(2): 189-95).

A pilot study in humans has also suggested a potential role for gp350vaccination in host protection against EBV. In a study by Gu et al.(Dev. Biol. Stand., 1995; 84:171-7) a single dose of gp350/220 expressedby vaccinia virus (VV) was given by scarification to 1- to 3-year-oldswho were EBV-seronegative, and VV-seronegative. These children developedneutralizing antibodies to EBV (1:40-1:160). Whereas 10/10 unvaccinatedcontrols became infected at 16 months of follow-up, only 3/9 vaccinatedchildren became infected at this time. More recently, Phase I/II studieswere conducted in which healthy EBV-seronegative adults were immunizedwith a recombinant monomeric gp350 protein in alum+/−monophosphoryllipid A. (Sokal et al., J. Infect. Dis., 2007 Dec. 15; 196(12):1749-53;and Moutschen et al., Vaccine, 2007 Jun. 11; 25(24):4697-705). Following3 doses, up to 82% of subjects had detectable neutralizing serumanti-gp350 antibody titers. The vaccine demonstrated an efficacy of78.0% in preventing the development of infectious mononucleosis but notin preventing asymptomatic EBV infection. Finally, an additional phase Itrial of recombinant monomeric gp350 protein in alum given to childrenwith chronic kidney disease demonstrated only a minority of subjectsdeveloping detectable neutralizing serum anti-gp350 titers. (Rees etal., Transplantation, 2009 Oct. 27; 88(8):1025-9).

There is currently no effective immunotherapy for EBV-associateddiseases, or a clinically licensed prophylactic EBV vaccine. EBV gp350,gH/gL complex, and gB are three envelope proteins that representpotential vaccine target antigens for EBV. EBV gp350 mediates EBVattachment to B cells through its binding to CD21. EBV gH/gL and gB areinvolved in mediating EBV fusion and entry into both B cells andepithelial cells.

EBV gp350/gp220. The EBV glycoprotein gp350 and the related splicevariant gp220 are responsible for attachment of EBV with high affinityto CR2 on B cells. Antibodies to gp350 or gp220 that block EBV bindingneutralize B-cell infection. Each of gp350 and gp220 is a highlyglycosylated single-pass membrane protein. As a result of alternativesplicing, the viral glycoprotein appears in two forms, with approximatemasses of 350 and 220 kDa. The 200 kDa splice form lacks residues500-757 of the full length gp350. Both gp350 and gp220 retain the CR2binding domain at the amino terminus. A truncated version of gp350 orgp220 having amino acids 1-470 of gp350 retains the ability to bind CR2and can inhibit the binding of EBV to CR2 and can be substituted forfull length gp350 or gp200 in the compositions described herein or forextracellular domain forms of gp350. (Sarrias et al., J. Immunol., 2001Aug. 1; 167(3):1490-9). In addition, portions of the gp350 and gp220protein between amino acids 21-26 or between amino acids 372-378 of thegp350 sequence have been linked to CR2 binding. (Tanner et al., Cell,203-213 (1987), and Nemerow et al., Cell, 61:1416-20, 1987). Thus, theterm gp350 protein or gp350 antigen (or gp220 protein or antigen) refersto the full length gp350 or gp220 proteins as well as fragments ormodified versions thereof that retain the ability to bind the CR2.

The amino acid and nucleic acid sequence of gp350, set forth in GenBankunder Accession Number M10593, Version M10593.1, GI 330360, is herebyincorporated by reference. The amino acid sequence of gp350 is (SEQ IDNO: 1):

MEAALLVCQY TIQSLIHLTG EDPGFFNVEI PEFPFYPTCN VCTADVNVTI  50NFDVGGKKHQ LDLDFGQLTP HTKAVYQPRG AFGGSENATN LFLLELLGAG 100ELALTMRSKK LPINVTTGEE QQVSLESVDV YFQDVFGTMW CHHAEMQNPV 150YLIPETVPYI KWDNCNSTNI TAVVRAQGLD VTLPLSLPTS AQDSNFSVKT 200EMLGNEIDIE CIMEDGEISQ VLPGDNKFNI TCSGYESHVP SGGILTSTSP 250VATPIPGTGY AYSLRLTPRP VSRFLGNNSI LYVFYSGNGP KASGGDYCIQ 300SNIVFSDEIP ASQDMPTNTT DITYVGDNAT YSVPMVTSED ANSPNVTVTA 350FWAWPNNTET DFKCKWTLTS GTPSGCENIS GAFASNRTFD ITVSGLGTAP 400KTLIITRTAT NATTTTHKVI FSKAPESTTT SPTLNTTGFA DPNTTTGLPS 450STHVPTNLTA PASTGPTVST ADVTSPTPAG TTSGASPVTP SPSPWDNGTE 500SKAPDMTSST SPVTTPTPNA TSPTPAVTTP TPNATSPTPA VTTPTPNATS 550PTLGKTSPTS AVTTPTPNAT SPTLGKTSPT SAVTTPTPNA TSPTLGKTSP 600TSAVTTPTPN ATGPTVGETS PQANATNHTL GGTSPTPVVT SQPKNATSAV 650TTGQHNITSS STSSMSLRPS SNPETLSPST SDNSTSHMPL LTSAHPTGGE 700NITQVTPASI STHHVSTSSP EPRPGTTSQA SGPGNSSTST KPGEVNVTKG 750TPPQNATSPQ APSGQKTAVP TVTSTGGKAN STTGGKHTTG HGARTSTEPT 800TDYGGDSTTP RPRYNATTYL PPSTSSKLRP RWTFTSPPVT TAQATVPVPP 850TSQPRFSNLS MLVLQWASLA VLTLLLLLVM ADCAFRRNLS TSHTYTTPPY 900DDAETYV                                                907

The amino acid sequence of gp220, set forth in GenBank under AccessionNumber M10593, Version M10593.1, GI 330360, and hereby incorporated byreference, is (SEQ ID NO: 2):

MEAALLVCQY TIQSLIHLTG EDPGFFNVEI PEFPFYPTCN VCTADVNVTI  50NFDVGGKKHQ LDLDFGQLTP HTKAVYQPRG AFGGSENATN LFLLELLGAG 100ELALTMRSKK LPINVTTGEE QQVSLESVDV YFQDVFGTMW CHHAEMQNPV 150YLIPETVPYI KWDNCNSTNI TAVVRAQGLD VTLPLSLPTS AQDSNFSVKT 200EMLGNEIDIE CIMEDGEISQ VLPGDNKFNI TCSGYESHVP SGGILTSTSP 250VATPIPGTGY AYSLRLTPRP VSRFLGNNSI LYVFYSGNGP KASGGDYCIQ 300SNIVFSDEIP ASQDMPTNTT DITYVGDNAT YSVPMVTSED ANSPNVTVTA 350FWAWPNNTET DFKCKWTLTS GTPSGCENIS GAFASNRTFD ITVSGLGTAP 400KTLIITRTAT NATTTTHKVI FSKAPESTTT SPTLNTTGFA DPNTTTGLPS 450STHVPTNLTA PASTGPTVST ADVTSPTPAG TTSGASPVTP SPSPWDNGTE 500STPPQNATSP QAPSGQKTAV PTVTSTGGKA NSTTGGKHTT GHGARTSTEP 550TTDYGGDSTT PRPRYNATTY LPPSTSSKLR PRWTFTSPPV TTAQATVPVP 600PTSQPRFSNL SMLVLQWASL AVLTLLLLLV MADCAFRRNL STSHTYTTPP 650YDDAETYV                                               658

EBV gH, gL, gB, and gp42. The minimal requirement for viral fusion withB cells includes EBV glycoproteins gH, gL, gB, and gp42. For infectionof B cells, gp42 binds to the host cell MHC class II molecules totrigger viral cell membrane fusion. On the other hand, for infection ofepithelial cells, gp42 is not required. Rather, the EBV gH, gL, and gBproteins are sufficient for viral fusion with epithelial cells. EBVgH/gL exists in certain environments as a noncovalently associatedcomplex.

The amino acid sequence of EBV gH is (SEQ ID NO: 4):

MQLLCVFCLV LLWEVGAASL SEVKLHLDIE GHASHYTIPW TELMAKVPGL 50

SPEALWREAN VTEDLASMLN RYKLIYKTSG TLGIALAEPV DIPAVSEGSM 100QVDASKVHPG VISGLNSPAC MLSAPLEKQL FYYIGTMLPN TRPHSYVFYQ 150LRCHLSYVAL SINGDKFQYT GAMTSKFLMG TYKRVTEKGD EHVLSLIFGK 200TKDLPDLRGP FSYPSLTSAQ SGDYSLVIVT TFVHYANFHN YFVPNLKDMF 250SRAVTMTAAS YARYVLQKLV LLEMKGGCRE PELDTETLTT MFEVSVAFFK 300VGHAVGETGN GCVDLRWLAK SFFELTVLKD IIGICYGATV KGMQSYGLER 350LAAVLMATVK MEELGHLTTE KQEYALRLAT VGYPKAGVYS GLIGGATSVL 400LSAYNRHPLF QPLHTVMRET LFIGSHVVLR ELRLNVTTQG PNLALYQLLS 450TALCSALEIG EVLRGLALGT ESGLFSPCYL SLRFDLTRDK LLSMAPQEAM 500LDQAAVSNAV DGFLGRLSLE REDRDAWHLP AYKCVDRLDK VLMIIPLINV 550TFIISSDREV RGSALYEAST TYLSSSLFLS PVIMNKCSQG AVAGEPRQIP 600KIQNFTRTQK SCIFCGFALL SYDEKEGLET TTYITSQEVQ NSILSSNYFD 650FDNLHVHYLL LTTNGTVMEI AGLYEERAHV VLAIILYFIA FALGIFLVHK 700IVMFFL                                                 706

The amino acid sequence of EBV gL is (SEQ ID NO: 5):

MRTVGVFLAT CLVTIFVLPT WGNWAYPCCH VTQLRAQHLL ALENISDIYL 50VSNQTCDGFS LASLNSPKNG SNQLVISRCA NGLNVVSFFI SILKRSSSAL 100TGHLRELLTT LETLYGSFSV EDLFGANLNR YAWHRGG 137

The amino acid sequence of EBV gB is (SEQ ID NO: 6):

MTRRRVLSVV VLLAALACRL GAQTPEQPAP PATTVQPTAT RQQTSFPFRV 50CELSSHGDLF RFSSDIQCPS FGTRENHTEG LLMVFKDNII PYSFKVRSYT 100KIVTNILIYN GWYADSVTNR HEEKFSVDSY ETDQMDTIYQ CYNAVKMTKD 150GLTRVYVDRD GVNITVNLKP TGGLANGVRR YASQTELYDA PGWLIWTYRT 200RTTVNCLITD MMAKSNSPFD FFVTTTGQTV EMSPFYDGKN KETFHERADS 250FHVRTNYKIV DYDNRGTNPQ GERRAFLDKG TYTLSWKLEN RTAYCPLQHW 300QTFDSTIATE TGKSIHFVTD EGTSSFVTNT TVGIELPDAF KCIEEQVNKT 350MHEKYEAVQD RYTKGQEAIT YFITSGGLLL AWLPLTPRSL ATVKNLTELT 400TPTSSPPSSP SPPAPPAARG STSAAVLRRR RRDAGNATTP VPPAAPGKSL 450GTLNNPATVQ IQFAYDSLRR QINRMLGDLA RAWCLEQKRQ NMVLRELTKI 500NPTTVMSSIY GKAVAAKRLG DVISVSQCVP VNQATVTLRK SMRVPGSETM 550CYSRPLVSFS FINDTKTYEG QLGTDNEIFL TKKMTEVCQA TSQYYFQSGN 600EIHVYNDYHH FKTIELDGIA TLQTFISLNT SLIENIDFAS LELYSRDEQR 650ASNVFDLEGI FREYNFQAQN IAGLRKDLDN AVSNGRNQFV DGLGELMDSL 700GSVGQSITNL VSTVGGLFSS LVSGFISFFK NPFGGMLILV LVAGVVILVI 750SLTRRTRQMS QQPVQMLYPG IDELAQQHAS GEGPGINPIS KTELQAIMLA 800LHEQNQEQKR AAQRAAGPSV ASRALQAARD RFPGLRRRRY HDPETAAALL 850 GEAETEF 857

The amino acid sequence of EBV gp42 is (SEQ ID NO: 7):

MVSFKQVRVP LFTAIALVIV LLLAYFLPPR VRGGGRVSAA AITWVPKPNV 50EVWPVDPPPP VNFNKTAEQE YGDKEIKLPH WTPTLHTFQV PKNYTKANCT 100YCNTREYTFS YKERCFYFTK KKHTWNGCFQ ACAELYPCTY FYGPTPDILP 150VVTRNLNAIE SLWVGVYRVG EGNWTSLDGG TFKVYQIFGS HCTYVSKFST 200VPVSHHECSF LKPCLCVSQR SNS 223

The amino acid sequence of EBV BMRF-2 is (SEQ ID NO: 8):

MFSCKQHLSL GACVFCLGLL ASTPFIWCFV FANLLSLEIF SPWQTHVYRL 50GFPTACLMAV LWTLVPAKHA VRAVTPAIML NIASALIFFS LRVYSTSTWV 100SAPCLFLANL PLLCLWPRLA IEIVYICPAI HQRFFELGLL LACTIFALSV 150VSRALEVSAV FMSPFFIFLA LGSGSLAGAR RNQIYTSGLE RRRSIFCARG 200DHSVASLKET LHKCPWDLLA ISALTVLVVC VMIVLHVHAE VFFGLSRYLP 250LFLCGAMASG GLYLGHSSII ACVMATLCTL TSVVVYFLHE TLGPLGKTVL 300FISIFVYYFS GVAALSAAMR YKLKKFVNGP LVHLRVVYMC CFVFTFVEYL 350 LVTFIKS

The amino acid sequence of EBV BDLF2 is (SEQ ID NO: 9):

MVDEQVAVEH GTVSHTISRE EDGVVHERRV LASGERVEVF YKAPAPRPRE 50GRASTFHDFT VPAAAAVPGP EPEPEPHPPM PIHANGGGET KTNTQDQNQN 100QTTRTRTNAK AEERTAEMDD TMASSGGQRG APISADLLSL SSLTGRMAAM 150APSWMKSEVC GERMRFKEDV YDGEAETLAE PPRCFMLSFV FIYYCCYLAF 200LALLAFGFNP LFLPSFMPVG AKVLRGKGRD FGVPLSYGCP TNPFCKVYTL 250IPAVVINNVT YYPNNTDSHG GHGGFEAAAL HVAALFESGC PNLQAVTNRN 300RTFNVTRASG RVERRLVQDM QRVLASAVVV MHHHCHYETY YVFDGVGPEF 350GTIPTPCFKD VLAFRPSLVT NCTAPLKTSV KGPNWSGAAG GMKRKQCRVD 400RLTDRSFPAY LEEVMYVMVQ

The antigenic compositions and methods of this application typicallyinvolve two or more HHV proteins involved in mediating HHV binding,fusion, and entry into host cells. In certain embodiments, two or moreEBV proteins disclosed herein are combined in an antigenic composition.The two or more EBV proteins can be administered simultaneously orseparately to induce an immune response or to treat or prevent an EBVinfection in a subject. In certain embodiments, the antigeniccomposition (or method of administration) comprises two or more of thefollowing EBV polypeptides (or nucleic acids encoding the same): gB, gH,gL, and gp350. In some embodiments, the gB polypeptide is monomeric,dimeric, or trimeric. In some embodiments, the gH and gL polypeptidesare monomeric, dimeric, trimeric, or tetrameric. Typically, gH and gLform a gH/gL heterodimer. In some embodiments, the gp350 polypeptidesare monomeric, dimeric, trimeric, or tetrameric.

In certain embodiments, the two or more EBV proteins (or nucleic acidsencoding the same) comprise a monomeric or multimeric gp350 andmonomeric or multimeric gB. In certain embodiments, the gp350 ismonomeric or tetrameric and the gB is monomeric or trimeric. In certainembodiments, the gp350 is monomeric and the gB is trimeric. In certainembodiments, the gp350 is tetrameric and the gB is trimeric.

In certain embodiments, the two or more EBV proteins (or nucleic acidsencoding the same) comprise a monomeric or multimeric gp350 and amonomeric or multimeric gH/gL heterodimer. In certain embodiments, thegp350 is monomeric or tetrameric and the gH/gL heterodimer is monomericor trimeric. In certain embodiments, the gp350 is monomeric and thegH/gL heterodimer is monomeric. In certain embodiments, the gp350 istetrameric and the gH/gL heterodimer is trimeric.

In certain embodiments, the two or more EBV proteins (or nucleic acidsencoding the same) comprise a monomeric or multimeric gB and a monomericor multimeric gH/gL heterodimer. In certain embodiments, the gB ismonomeric, dimeric or trimeric and the gH/gL heterodimer is monomeric ortrimeric. In certain embodiments, the gB is monomeric and the gH/gLheterodimer is monomeric or trimeric. In certain embodiments, the gB istrimeric and the gH/gL heterodimer is monomeric. In certain embodiments,the gB is trimeric and the gH/gL heterodimer is trimeric. In certainembodiments, the EBV gB, gH, and gL polypeptides form a protein complexwhen mixed together. In certain embodiments, the EBV gB, gH, and gLpolypeptides are not administered as a protein complex comprising thegB, gH, and gL polypeptides. For example, the gB can be administeredseparately from the gH and/or gL or administered with the gH and gL butnot as a protein complex.

In certain embodiments, the two or more EBV proteins (or nucleic acidsencoding the same) comprise a monomeric or multimeric gp350, a monomericor multimeric gB and a monomeric or multimeric gH/gL heterodimer. Incertain embodiments, the gp350 is monomeric or tetrameric, the gB ismonomeric or trimeric and the gH/gL heterodimer is monomeric ortrimeric. In certain embodiments, the gp350 is monomeric, the gB istrimeric and the gH/gL heterodimer is monomeric. In certain embodiments,the gp350 is tetrameric, the gB is trimeric and the gH/gL heterodimer istrimeric.

In some embodiments, the two or more EBV proteins further comprises oneor more of a BMRF-2 polypeptide, a BDLF2 polypeptide, and/or a gp42polypeptide, which can be monomeric or multimeric (e.g., dimeric,trimeric, or tetrameric).

Kaposi's Sarcoma Virus-Associated Herpes (KSHV, HHV-8). The two humangammaherpesviruses, Epstein-Barr virus (EBV), a gamma 1lymphocryptovirus, and Kaposi's sarcoma associated virus (KSHV), a gamma2 rhadinovirus, have many features in common. They share an architecturethat is typical of all members of the herpesvirus family, they share anability to establish latency in lymphocytes, and they are bothinitiators or potentiators of human tumors. (Chandran et al., HumanHerpesviruses: Biology, Therapy, and Imunoprophylaxis, Eds. Arvin, A.,Campadelli-Fiume, G., and Mocarski E., et al., Cambridge UniversityPress, 2007, Ch. 23). KSHV broadly infects many types of host cells,including B-cells from the peripheral blood, B-cells in primary effusionlymphomas (PEL) or body-cavity based B-cell lymphomas (BCBL) andmulticentric Cattleman's disease (MCD), flat endothelial cells liningthe vascular spaces of Kaposi's sarcoma (KS) lesions, typical KS spindlecells, CD 45+/CD68+ monocytes in KS lesions, keratinocytes, andepithelial cells. (Id.). Further, KSHV infection has been associatedwith multiple myeloma. (Rettig et al., Science, 276:1851-4, 1997). LikeEBV, KSHV also expresses gB, gH, and gL that mediate cell fusion andentry. KSHV also expresses the conserved glycoproteins, gM and gN, whichmediate similar, if not identical, roles as compared to their EBVcounterparts. (Id.).

However, the gp350 glycoprotein of EBV is replaced in KSHV with apolypeptide termed K8.1. The K8.1 gene encodes a 197-amino acid with apredicted molecular weight of about 22 kDa and possessing no sequencecorresponding to a TM domain. Similar to the EBV gp350/220, the KSHVK8.1 gene encodes two ORF s, designated gpK8.1A and gpK8.1B, fromspliced messages. The larger cDNA is 752 bp long (76,214-76,941 bp) andutilizes the polyadenylation signal sequence (AATAAA) at position 77 013bp. The 228-aa long encoded protein is designated gpK8.1A, whichcontains a signal sequence, transmembrane domain, and fourN-glycosylation sites. Otherwise, the KSHV gpK18.1 polypeptide performssimilar functions as reported for EBV gp350, forming a complex with gBand binding to a cell surface heparin sulfate molecule on the host cell.

KSHV ORF68 is a late lytic, delayed early structural and assembly geneencoding a transmembrane glycoprotein that is a component of the KSHVenvelope. (Nakamura et al., J. Virol., 77(7):4205-20, 2003; and Jha etal., mBio, 5(6):e02261-14, 2014; and Stürzl et al., Thromb. Haemost.,102:1117-34, 2009). ORF68 is known to interact with and inhibit the hostcell's ubiquitin proteasome pathway, thereby inhibiting proteindegradation. (Gardner, M., 8^(th) Annual CEND Symposium, 22 Mar. 2016).ORF68 is essential for viral genome replication in KSHV. It ispostulated that KSHV ORF68 encodes a protein that suppresses theproteasome-mediated degradation of a protein in the cytoplasm of thehost cell that is essential for KSHV DNA replication. (Id.).

The antigenic compositions and methods of this application typicallyinvolve two or more HHV proteins involved in mediating HHV binding,fusion, and entry into host cells. In certain embodiments, two or moreKSHV proteins disclosed herein are combined in an antigenic composition.The two or more KSHV proteins can be administered simultaneously orseparately to induce an immune response or to treat or prevent a KSHVinfection in a subject. In certain embodiments, the antigeniccomposition (or method of administration) comprises two or more of thefollowing KSHV polypeptides (or nucleic acids encoding the same): gB,gH, and gL. In some embodiments, the gB polypeptide is monomeric,dimeric, or trimeric. In some embodiments, the gH and gL polypeptidesare monomeric, dimeric, trimeric, or tetrameric. Typically, gH and gLform a gH/gL heterodimer.

In certain embodiments, the two or more KSHV proteins (or nucleic acidsencoding the same) comprise a monomeric or multimeric gB and a monomericor multimeric gH/gL heterodimer. In certain embodiments, the gB ismonomeric, dimeric or trimeric and the gH/gL heterodimer is monomeric ortrimeric. In certain embodiments, the gB is monomeric and the gH/gLheterodimer is monomeric or trimeric. In certain embodiments, the gB istrimeric and the gH/gL heterodimer is monomeric. In certain embodiments,the gB is trimeric and the gH/gL heterodimer is trimeric. In certainembodiments, the KSHV gB, gH, and gL polypeptides form a protein complexwhen mixed together. In certain embodiments, the KSHV gB, gH, and gLpolypeptides are not administered as a protein complex comprising thegB, gH, and gL polypeptides. For example, the gB can be administeredseparately from the gH and/or gL or administered with the gH and gL butnot as a protein complex.

In certain embodiments, the two or more KSHV proteins further comprisesone or more of the gN polypeptide, the gM polypeptide, the ORF68polypeptide and/or the gpK8.1 polypeptide, which can be monomeric ormultimeric (e.g., dimeric, trimeric, or tetrameric).

The amino acid and nucleic acid sequence of KSHV gpK8.1A, set forth inGenBank under Accession Number AAC63270.1, GI 3414867, is herebyincorporated by reference. The amino acid sequence of gpK8.1 is (SEQ IDNO: 10):

1 MSSTQIRTEI PVALLILCLC LVACHANCPT YRSHLGFWQE GWSGQVYQDW LGRMNCSYEN 61MTALEAVSLN GTRLAAGSPS SEYPNVSVSV EDTSASGSGE DAIDESGSGE EERPVTSHVT 121FMTQSVQATT ELTDALISAF SGSYSSGEPS RTTRIRVSPV AENGRNSGAS NRVPFSATTT 181TTRGRDAHYN AEIRTHLYIL WAVGLLLGLV LILYLCVPRC RRKKPYIV

The amino acid and nucleic acid sequence of KSHV gpK8.1B, set forth inGenBank under Accession Number AJE29698.1, GI 748016404, and herebyincorporated by reference. The amino acid sequence of gpK8.1B is (SEQ IDNO: 11):

1 MSSTQIRTEI PVALLILCLC LVACHANCPT YRSHLGFWQE GWSGQVYQDW LGRMNCSYEN 61MTALEAVSLN GTRLAAGSPS RSYSSGEPSR TTRIRVSPVA ENGRNSGASN RVPFSATTTT 121TRGRDAHYNA EIRTHLYILW AVGLLLGLVL ILYLCVPRCR RKKPYIV

The amino acid sequence of KSHV gH is (SEQ ID NO: 12):

MQGLAFLAAL ACWRCISLTC GATGALPTTA TTITRSATQL INGRTNLSIE 50LEFNGTSFFL NWQNLLNVIT EPALTELWTS AEVAEDLRVT LKKRQSLFFP 100NKTVVISGDG HRYTCEVPTS SQTYNITKGF NYSALPGHLG GFGINARLVL 150GDIFASKWSL FARDTPEYRV FYPMNVMAVK FSISIGNNES GVALYGVVSE 200DFVVVTLHNR SKEANETASH LLFGLPDSLP SLKGHATYDE LTFARNAKYA 250LVAILPKDSY QTLLTENYTR IFLNMTESTP LEFTRTIQTR IVSIEARRAC 300AAQEAAPDIF LVLFQMLVAH FLVARGIAEH RFVEVDCVCR QYAELYFLRR 350ISRLCMPTFT TVGYNHTTLG AVAATQIARV SATKLASLPR SSQETVLAMV 400QLGARDGAVP SSILEGIAMV VEHMYTAYTY VYTLGDTERK LMLDIHTVLT 450DSCPPKDSGV SEKLLRTYLM FTSMCTNIEL GEMIARFSKP DSLNIYRAFS 500PCFLGLRYDL HPAKLRAEAP QSSALTRTAV ARGTSGFAEL LHALHLDSLN 550LIPAINCSKI TADKIIATVP LPHVTYIISS EALSNAVVYE VSEIFLKSAM 600FISAIKPDCS GFNFSQIDRH IPIVYNISTP RRGCPLCDSV IMSYDESDGL 650QSLMYVTNER VQTNLFLDKS PFFDNNNLHI HYLWLRDNGT VVEIRGMYRR 700RAASALFLIL SFIGFSGVIY FLYRLFSILY

The amino acid sequence of KSHV gL is (SEQ ID NO: 13):

MGIFALFAVL WTTLLVTSHA YVALPCCAIQ ASAASTLPLF FAVHSIHFAD 50PNHCNGVCIA KLRSKTGDIT VETCVNGFNL RSFLVAVVRR LGSWASQENL 100RLLWYLQRSL TAYTVGFNAT TADSSIHNVN IIIISVGKAM NRTGSVSGSQ 150TRAKSSSRRA HAGQKGK

The amino acid sequence of KSHV gB is (SEQ ID NO: 12):

MQGLAFLAAL ACWRCISLTC GATGALPTTA TTITRSATQL INGRTNLSIE 50LEENGTSFEL NWQNLLNVIT ETALTELWTS AEVAEDLRVT LKKRQSLFFP 100NKTVVISGDG HRYTCEVPTS SQTYNITKGF NYSALPGHLG GEGINAPIVL 150GDIFASKWSL FARDIPEYRV FYPMNVMAVK FSISIGNNES GVALYGVVSE 200DFVVVTLHNR SKEANETASH LLFGLPDSLP SLKGHATYDE LTFARNAKYA 250LVAILPKDSY QTLLTENYTR IELNMTESTP LEFTRTIQTR IVSIEARRAC 300AAQEAAPDTF LVLFQMLVAH FLVARGIAEH RFVEVDCVCR QYAELYFLRR 350ISPICMPTFT TVGYNHTTLG AVAATQIARV SATKLASLPR SSQETVLAMV 400QLGARDGAVP SSILEGIAMV VEHMYTAYTY VYTLGDTERK LMLDINTVLT 450DSCPPKDSGV SEKLLRTYLM FTSMCTNIEL GEMIARFSKP DSLNRYRAFS 500PCFLGLRYDL NPAKLRAEAP QSSALTRTAV ARGTSGFAEL LHALNLDSLN 550LIPAINCSKI TADKIIATVP LPHVTYIISS EALSNAVVYE VSEIFLKSAM 600FISAIKPDCS GFNFSQIDRH IPIVYNISTP RRGCPLCDSV IMSYDESDGL 650QSLMYVTNER VQ7NLELDKS PFEDNNNLHI NYLWLRDNGT VVEIRGMYRR 700PAASALFLIL SFIGFSGVIY FLYRLFSILY

The amino acid sequence of KSHV gN is (SEQ ID NO: 14):

MTASTVALAL FVASILGHCW VTANSTGVAS STERSSPSTA GLSARPSPGP 50TSVTTPGFYD VACSADSFSP SLSSFSSVWA LINALLVVVA TFFYLVYLCF 100 FKFVDEVVHA

The amino acid sequence of KSHV gM is (SEQ ID NO: 15):

MRASKSDRFL MSSWVKLLFV AVIMYICSAV VPMAATYEGL GFPCYFNNLV 50NYSALNLTVR NSAKHLTPTL FLEKPEMLVY IFWTFIVDGI AIVYYCLAAV 100AVYRAKHVHA TTMMSMQSWI ALLGSHSVLY VAILRMWSMQ LFIHVLSYKH 150VLMAAFVYCI HFCISFAHIQ SLITCNSAQW EIPLLEQHVP DNTMMESLLT 200RWKPVCVNLY LSTTALEMLL FSLSTMMAVG NSFYVLVSDA IFGAVNMFLA 250LTVVWYINTE FFLVKFMRRQ VGFYVGVFVG YLILLLPVIR YENAFVQANL 300HYIVAINISC IPILCILAIV IRVIRSDWGL CTPSAAYMPL ATSAPTVDRT 350PTVHQKPPPL PAKTRARAKV KDISTPAPRT QYQSDHESDS EIDETQMIFI 400

The amino acid sequence of KSHV ORF68 is (SEQ ID NO: 16):

MFVPWQLGTI TRHRDELQKL LAASLLPEHP EESLGNPIMT QIHQSLQPSS 50PCRVCQLLFS LVRDSSTPMG FFEDYACLCF FCLYAPHCWT STMAAAADLC 100EIMHLHFPEE EATYGLFGPG RLMGIDLQLH FFVQKCFKTT AAEKILGISN 150LQFLKSEFIR GMLTGTITCN FCFKTSWPRT DKEEATGPTP CCQITDTTTA 200PASGIPELAR ATFCGASRPT KPSLLPALID IWSTSSELLD EPRPRLIASD 250MSELKSVVAS HDPFFSPPLQ ADTSQGPCLM HPTLGLRYKN GTASVCLLCE 300CLAAHPEAPK ALQTLQCEVM GHIENNVKLV DRIAFVLDNP FAMPYVSDPL 350LRELIRGCTP QEIHKHLFCD PLCALNAKVV SEDVLFRLPR EQEYKKLRAS 400AAAGQLLDAN TLFDCEVVQT LVFLFKGLQN ARVGKTTSLD IIRELTAQLK 450RHRLDLAHPS QTSHLYA

Betaherpesviruses: Human Cytomegalovirus (HCMV, HHV-5); Human HerpesVirus 6 (HHV-6); & Human Herpes Virus 7 (HHV-7)

Human Cytomegalovirus (HCMV, HHV-5). Human cytomegalovirus (HCMV) is anenveloped, double-stranded DNA β-herpesvirus of the Herpesviridae familyHCMV further belongs to the betaherpesvirus subfamily, of which HHV-6and HHV-7 are also members. Cells infected with this family of virusesoften become enlarged (cytomegaly). HCMV is the leading non-geneticcause of hearing loss in childhood and a significant cause ofneurodevelopmental delay, including mental retardation.(Demmler-Harrison G J, J. Clin. Virol., 46 Suppl 4, 2009: S1-5; Jeon etal., Infect. Dis. Obstet. Gynecol., 2006:80383, 2006; and Morton et al.,N Engl. J. Med., 354:2151-64, 2006). In the U.S., between 20,000 and40,000 infants per year are born with HCMV infection, accounting for anannual 8,000 permanent disabilities and a healthcare cost of S1.86billion. HCMV also causes significant clinical diseases inimmunosuppressed individuals, including transplant recipients andpatients with AIDS. (Bonaros et al., Clin. Transplant., 22:89-97, 2008;and Steininger et al., J. Clin. Virol., 37:1-9, 2006). Although HCMVinfection in immunocompetent individuals is generally asymptomatic, itmay produce a mononucleosis syndrome in 10% of primary infections ofolder children and adults. (Horwitz et al., Medicine (Baltimore),65:124-34, 1986). In 2001, the Institute of Medicine of the U.S.National Academy of Sciences stated that a vaccine to prevent congenitalHCMV infection is among the highest U. S. priorities. (Stratton et al.,“Vaccines for the 21st Century: A tool for decisionmaking,” Washington,D.C., National Academy Press, 2001).

HCMV is spread mainly through saliva and urine, and via transplacentaltransmission to the fetus (Krause et al., Vaccine, 32:4-10, 2014). HCMVcan also be transmitted to infants through breast milk (Maschmann etal., Clin. Infect. Dis., 33:1998-2003, 2001), through sexual activity,through solid organ or hematopoietic stem cell transplantation, andrarely by transfusion of blood products. HCMV primarily infectsfibroblasts, epithelial cells, endothelial cells, monocyte-macrophages,hepatocytes, and neurons. The mechanism of HCMV fusion and entry intomammalian cells is analogous to that employed by other members of theherpesvirus family (Heldwein et al., Cell. Mol. Life Sci., 65:1653-68,2008; and White et al., Crit. Rev. Biochem. Mol. Biol., 43:189-219,2008). HCMV enters cells by fusing its envelope with either the plasmamembrane (fibroblasts) (Compton et al., Virology, 191:387-95, 1992) orendosomal membrane (epithelial and endothelial cells) (Ryckman et al.,J. Virol., 80:710-22, 2006).

HCMV gB, gH, gL, gO (UL74), gM, gN (gpUL73), and UL128/130/131A. Thenine glycoproteins gB, gH, gL, gO (UL74), gM, gN (gpUL73), andUL128/130/131A, have collectively been identified as the envelopeglycoproteins that play important roles in HCMV fusion and entry intohost cells (Hahn et al., J. Virol., 78:10023-33, 2004; Ryckman et al.,J. Virol., 82:60-70, 2008; Wang et al., Proc. Natl. Acad. Sci. USA,102:18153-8, 2005; and Wille et al., J. Virol., 84:2585-96, 2010).Similar to gammaherpesvirus family members, HCMV gH/gL and gB proteinsplay an important role in HCMV fusion and entry into host cells. The gBprotein is the direct mediator of HCMV fusion with all host cellmembranes. Activation of HCMV gB and its fusogenic activity requiresassociation with gH/gL and gO, which together form a gH/gL/gOheterotrimer protein complex. However, the gH/gL/UL128/130/131A(pentameric complex) protein is also important for efficient targetingof HCMV to epithelial and endothelial cells, since UL128/130/131Amutants failed to infect these cells (Ryckman et al., J. Virol.,80:710-22, 2006; Hahn et al., J. Virol., 78:10023-33, 2004; Adler etal., J. Gen. Virol., 87: 2451-60, 2006; and Wang et al., J. Virol.,79:10330-8, 2005). In contrast, gO seems to be involved in HCMV fusionwith all HCMV host cells, since gO null HCMV failed to infect all celltypes tested including fibroblasts, epithelial and endothelial cells,and infection of both fibroblasts and epithelial cells was generallycorrelated with the abundance of gH/gL/gO complex, but not withpentameric complex gH/gL/UL128/UL130/UL131A (Wille et al., J. Virol.,84:2585-96, 2010; Jiang et al., J. Virol., 82:2802-12, 2008; and Zhou etal., J. Virol., 89(17):8999-9009, 2015). All three of the UL128-131genes share a common architecture including an amino-terminal signalpeptide, a central chemokine-like domain, and a carboxy-terminal domainwith no homology to any known class of proteins. (Patrone et al., J.Virol., 79(13):8361-8373, 2005). HCMV gB or gH/gL proteins have beenshown to elicit serum HCMV neutralizing antibodies for both fibroblastsand epithelial cells. However, the pentameric complex induces thehighest serum neutralizing titers for epithelial and endothelial cells,though with no further improvement for fibroblasts (Wen et al., Vaccine,32:3796-804, 2014; Freed et al., Proc. Natl. Acad. Sci. USA,110:E4997-5005, 2013; and Schuessler et al., J. Virol., 86:504-12,2012). Although an HCMV gH/gL/gO complex was produced in mammalian cells(HEK-239) (Kinzler et al., J. Clin. Virol., 25 Suppl 2:S87-95, 2002),there have been no reports on its ability to induce HCMV neutralizingantibodies.

The glycoprotein M and N polypeptides are glycoprotein complex II (GCII)antigens. Glycoprotein N is an envelope component of the mature viralparticle with a portion exposed at the virus surface and a portionextending to the internal side of the envelope. It is present in thematrix of defense bodies and “block holes.” (Pignatelli, et al., Arch.Virol., 147:1247, 2002). HCMV gM polypeptide is 372 amino acids inlength and has an approximate molecular weight of 42 kDa, possessingseven TM domains. HCMV gN is 129 amino acids in length and has apredicted molecular weight of about 15 kDa, but due to heavyglycosylation tends to appear as a 40 to 50 kDa protein. Theglycoprotein M (gM, UL100) and glycoprotein N (gN, UL73) form a gM/gNprotein complex which is the most abundant protein component of the HCMVenvelope. Recent studies have indicated that deletion of the viral geneencoding either gM or gN is lethal for HCMV, but not for other HHV.(Baines et al., J. Virol., 67:1441-1452, 1993; Fuchs et al., Virus Res.,112:108-114, 2005; Hobom et al., J. Virol., 74:7720-7729, 2000; Mach etal., J. Virol., 81:5212-5224, 2007; and MacLean et al., J. Gen. Virol.,74 (pt. 6):975-983, 1993).

The antigenic compositions and methods of this application typicallyinvolve two or more HHV proteins involved in mediating HHV binding,fusion, and entry into host cells. In certain embodiments, two or moreHCMV proteins disclosed herein are combined in an antigenic composition.The two or more HCMV proteins can be administered simultaneously orseparately to induce an immune response or to treat or prevent an HCMVinfection in a subject. In certain embodiments, the antigeniccomposition (or method of administration) comprises two or more of thefollowing HCMV polypeptides (or nucleic acids encoding the same): gB,gH, and gL. In some embodiments, the gB polypeptide is monomeric,dimeric, or trimeric. In some embodiments, the gH and gL polypeptidesare monomeric, dimeric, trimeric, or tetrameric. Typically, gH and gLform a gH/gL heterodimer.

In certain embodiments, the two or more HCMV proteins (or nucleic acidsencoding the same) comprise a monomeric or multimeric gB and a monomericor multimeric gH/gL heterodimer. In certain embodiments, the gB ismonomeric, dimeric or trimeric and the gH/gL heterodimer is monomeric ortrimeric. In certain embodiments, the gB is monomeric and the gH/gLheterodimer is monomeric or trimeric. In certain embodiments, the gB istrimeric and the gH/gL heterodimer is monomeric. In certain embodiments,the gB is trimeric and the gH/gL heterodimer is trimeric. In certainembodiments, the HCMV gB, gH, and gL polypeptides form a protein complexwhen mixed together. In certain embodiments, the HCMV gB, gH, and gLpolypeptides are not administered as a protein complex comprising thegB, gH, and gL polypeptides. For example, the gB can be administeredseparately from the gH and/or gL or administered with the gH and gL butnot as a protein complex.

In some embodiments, the two or more HCMV proteins (or nucleic acidsencoding the same) further comprises the gO polypeptide, which isoptionally multimeric (e.g., dimeric, trimeric, or tetrameric). In otherembodiments, the two or more HCMV proteins (or nucleic acids encodingthe same) further comprises a gN and/or a gM polypeptide, which can bemonomeric or multimeric (e.g., dimeric, trimeric, or tetrameric). Instill other embodiments, the two or more HCMV proteins (or nucleic acidsencoding the same) comprise the gB polypeptide, the gH polypeptide, thegL polypeptide, and the UL128, UL130, and UL131A polypeptides. Incertain embodiments, the two or more HCMV proteins (or nucleic acidsencoding the same) comprise trimeric gB, monomeric gH/gL and UL128,UL130, and UL131A, wherein UL128, UL130, and UL131A are preferablycombined as a fusion protein. In certain embodiments, these five HCMVpolypeptides are present in the composition as a pentameric proteincomplex. In certain embodiments, they are present in the composition asa fusion protein.

Also disclosed is a recombinant nucleic acid encoding a protein complexor a fusion protein comprising HHV polypeptides gH, gL, UL128, UL130,and UL131A. The sequences of these HHV polypeptides making up thepentameric complex can be from any betaherpesvirus subfamily member,including, for example, HCMV. An embodiment of a nucleic acid constructencoding all five HCMV polypeptides of the pentameric complex isdepicted in FIG. 13, including exemplary operably linked promotersequences and the like. Additional nucleic acid sequences can beincluded in such a nucleic acid sequence to aide in purification, suchas his-tag sequences or immunoglobulin kappa sequences, etc. known inthe art as protein purification tags, etc. In another embodiment, thenucleic acid construct can comprise sequences encoding the HHVpolypeptides gH, gL, and gB. These highly conserved polypeptides arefound in all HHV genomes and therefore can correspond to any known HHVgB, gH, and/or gL sequence.

The amino acid sequence of HCMV gH is (SEQ ID NO: 17):

MRPGLPPYLT VFTVYLLSHL PSQRYGADAA SEALDPHAFH LLLNTYGRPI 50RFLRENTTQC TYNSSLRNST VVRENAISFN FFQSYNQYYV FHMPRCLFAG 100PLAEQFLNQV DLTETLERYQ QRLNTYALVS KDLASYRSFS QQLKAQDSLG 150QQPTTVPPPI DLSIPHVWMP PQTTPHDWKG SHTTSGLHRP HFNQTCILFD 200GHDLLFSTVT PCLHQGFYLM DELRYVKITL TEDFFVVTVS IDDDTPMLLI 250FGHLPRVLFK APYQRDNFIL RQTEKHELLV LVKKAQLNRH SYLKDSDFLD 300AALDFNYLDL SALLRNSFHR YAVDVLKSGR CQMLDRRTVE MAFAYALALF 350AAARQEEAGT EISIPRALDR QAALLQIQEF MITCLSQTPP RTTLLLYPTA 400VDLAKRALWT PDQITDITSL VRLVYILSKQ NQQHLIPQWA LRQIADFALQ 450LHKTHLASFL SAFARQELYL MGSLVHSMLV HTTERREIFI VETGLCSLAE 500LSHFTQLLAH PHHEYLSDLY TPCSSSGRRD HSLERLTRLF PDATVPATVP 550AALSILSTMQ PSTLETFPDL FCLPLGESFS ALTVSEHVSY VVTNQYLIKG 600ISYPVSTTVV GQSLIITQTD SQTKCELTRN MHTTHSITAA LNISLENCAF 650CQSALLEYDD TQGVINIMYM HDSDDVLFAL DPYNEVVVSS PRTHYLMLLK 700NGTVLEVTDV VVDATDSRLL MMSVYALSAI IGIYLLYRML KTC

The amino acid sequence of HCMV gL is (SEQ ID NO: 18):

MCRRPDCGFS FSPGPVILLW CCLLLPIVSS AAVSVAPTAA EKVPAECPEL 50TRRCLLGEVF EGDKYESWLR PLVNVTGRDG PLSQLIRYRP VTPEAANSVL 100LDEAFLDTLA LLYNNPDQLR ALLTLLSSDT APRWMTVMRG YSECGDGSPA 150VYTCVDDLCR GYDLTRLSYG RSIFTEHVLG FELVPPSLFN VVVAIRNEAT 200RTNRAVRLPV STAAAPEGIT LFYGLYNAVK EFCLRHQLDP PLLRHLDKYY 250AGLPPELKQT RVNLPAHSRY GPQAVDAR

The amino acid sequence of HCMV gB is (SEQ ID NO: 19):

MESRIWCLVV CVNLCIVCLG AAVSSSSTSH ATSSTHNGSH TSRTTSAQTR  50SVYSQHVTSS EAVSHRANET IYNTTLKYGD VVGVNTTKYP YRVCSMAQGT 100DLIRFFRNII CTSMKPINED LDEGIMVVYK RNIVAHTENV RVYQKVLTER 150RSYAYIYTTY LLGSNTEYVA PPMWEIHHIN KFAQCYSSYS RVIGGTVFVA 200YHRDSYENKT MQLIPDDYSN THSTRYVTVK DQWHSRGSTW LYRETCNLNC 250MLTITTARSK YPYHFFATST GDVVYISPFY NGTNRNASYE GENADKFFIF 300PNYTIVSDFG RPNAAPETHR LVAFLERADS VISWDIQDEK NVTCQLTFWE 350ASERTIRSEA EDSYHFSSAK MTATELSKKQ EVNMSDSALD CVRDEAINKL 400QQIENTSYNQ TYEKYGNVSV FETSGGLVVF WQGIKQKSLV ELERLANRSS 450LNITHRTRRS TSDNNTTHLS SMESVHNLVY AQLQFTYDIL RGYINRALAQ 500IAEAWCVDQR RTLEVFNELS KINPSAILSA IYNKPIAARF MGDVLGLASC 550VTINQTSVKV LRDMNVKESP GRCYSRPVVI FNEANSSYVQ YGQLGEDNEI 600LLGNHRTEEC QLPSLKIFIA GNSAYEYVDY LFKRMIDLSS ISTVDSMIAL 650DIDPLENTDF RVLELYSQKE LRSSNVEDLE EIMREFNSYK QRVKYVEDKV 700VDPLPPYLKG LDDLMSGLGA AGKAVGVAIG AVGGAVASVV EGVATFLKNP 750FGAFTIILVA IAVVIITYLI YTRQRRLCTQ PLQNLFPYLV SADGTTVTSG 800STKDTSLQAP PSYEESVYNS GRKGPGPPSS DASTAAPPYT NEQAYQMLLA 850LARLDAEQRA QQNGTDSLDG QTGTQDKGQK PNLLDRLRHR KNGYRHLKDS 900 DEEENV

The amino acid sequence of HCMV gN is (SEQ ID NO: 20):

MEWNTLVLGL LVLSVVAESS GNNSSTSTSA TTSKSSASVS TTKLTTVATT  50SATTTTTTTL STTSTKLSST THDPNVMRRH ANDDFYKAHC TSHMYELSLS 100SFAAWWTMLN ALILMGAFCI VLRHCCFQNF TATTTKGY

The amino acid sequence of HCMV gM is (SEQ ID NO: 21):

MAPSHVDKVN TRTWSASIVF MVLTFVNVSV HLVLSNFPHL GYPCVYYHVV  50DFERLNMSAY NVMHLHTPML FLDSVQLVCY AVFMQLVFLA VTIYYLVCWI 100KISMRKDKGM SLNQSTRDIS YMGDSLTAFL FILSMDTFQL FTLTMSFRLP 150SMIAFMAAVH FFCLTIFNVS MVTQYRSYKR SLFFFSRLHP KLKGTVQFRT 200LIVNLVEVAL GFNTTVVAMA LCYGFGNNFF VRTGHMVLAV FVVYAIISII 250YFLLIEAVFF QYVKVQFGYH LGAFFGLCGL IYPIVQYDTF LSNEYRTGIS 300WSFGMLFFIW AMFTTCRAVR YFRGRGSGSV KYQALATASG EEVAVLSHHD 350SLESRRLREE EDDDDDEDFE DA

The amino acid sequence of HCMV gO is (SEQ ID NO: 22):

MGRKEMMVRD VPKMVFLISI SFLLVSFINC KVMSKALYNR PWRGLVLSKI  50GKYKLDQLKL EILRQLETTI STKYNVSKQP VKNLTMNMTE FPQYYILAGP 100IQNYSITYLW FDFYSTQLRK PAKYVYSQYN HTAKTITFRP PPCGTVPSMT 150CLSEMLNVSK RNDTGEQGCG NFTTFNPMFF NVPRWNTKLY VGPTKVNVDS 200QTIYFLGLTA LLLRYAQRNC THSFYLVNAM SRNLFRVPKY INGTKLKNTM 250RKLKRKQAPV KEQFEKKAKK TQSTTTPYFS YTTSAALNVT TNVTYSITTA 300ARRVSTSTIA YRPDSSFMKS IMATQLRDLA TWVYTTLRYR QNPFCEPSRN 350RTAVSEFMKN THVLIRNETP YTIYGTLDMS SLYYNETMFV ENKTASDSNK 400TTPTSPSMGF QRTFIDPLWD YLDSLLFLDE IRNFSLRSPT YVNLTPPEHR 450RAVNLSTLNS LWWWLQ

The amino acid sequence of HCMV UL128 is (SEQ ID NO: 23):

MSPKNLTPFL TALWLLLGHS RVPRVRAEEC CEFINVNHPP ERCYDFKMCN  50RFTVALRCPD GEVCYSPEKT AEIRGIVTTM THSLTRQVVH NKLTSCNYNP 100LYLEADGRIR CGKVNDKAQY LLGAAGSVPY RWINLEYDKI TRIVGLDQYL 150ESVKKHKRLD VCRAKMGYML Q

The amino acid sequence of HCMV UL130 is (SEQ ID NO: 24):

MLRLLLRHYF HCLLLCAVWA TPCLASSWST LTANQNPSPP WSKLTYSKPH  50DAATFYCPFL YPSPPRSPSQ FSGFQRVSTG PECRNETLYL LYNREGQTLV 100ERSSTWVKKV IWYLSGRNQT ILQRMPRTAS KPSDGNVQIS VEDAKIFGAH 150MVPKQTKLLR FVVNDGTRYQ MCVMKLESWA HVFRDYSVSF QVRLTFTEAN 200NQTYTFCTHP NLIV

The amino acid sequence of HCMV UL131A is (SEQ ID NO: 25):

MRLCRVWLSV CLCAVVLGQC QRETAEKNDY YRVPHYWDAC SRALPDQTRY  50KYVEQLVDLT LNYHYDASHG LDNFDVLKRI NVTEVSLLIS DFRRQNRRGG 100TNKRTTFNAA GSLAPHARSL EFSVRLFAN

Human Herpes Virus 6 (HHV-6) and Human Herpes Virus 7 (HHV-7). AlthoughHHV-6 and HHV-7 are distinct from HCMV in terms of genomic sequence,they retained a core of 80 herpesvirus-common ORFs that are alsoconserved in rodent CMVs. (Mocarski E., Cell. Microb., 6(8):707-717,2004). HHV-6 was first isolated in 1986 from peripheral blood leukocytesin patients presenting with lymphoproliferative disorders and AIDS.(Flamand et al., J. Virol., 67(11):6768-6777, 1993). It is estimatedthat about 90% of individuals are infected by HHV-6 by the age of two,and approaches 100% in non-industrialized countries. (Salahuddin et al.,Science, 234:596, 1986; Willis et al., Br. Med. Bull., 62(1):125-138,2002). HHV-6 infections cause roseola infantum (sixth disease), exanthemsubitum rash (roseola) and is associated with heterophile-negativeinfectious mononucleosis, as well as meningoencephalitis, hepatitis,fatal hemophagocytic syndrome, and interstitial pneumonitis. (Id.).Further, there is some evidence suggesting a role in HHV-6 in certaincancers due to the detection of its genomic sequences in some B-celllymphomas and the potential of HHV-6 to transform rodent cells. (Ablashiet al., J. Virol. Methods, 21:29-48, 1988; Josephs et al., Science,234:601-603, 1986; Razzaque, A., Oncogene, 5:1356-1370, 1990; andTorelli et al., Blood, 77:2251-2258, 1991). There are two variants ofHHV-6 confirmed by genetic sequencing: HHV-6A and HHV-6B. (Ablashi etal., Arch. Virol., 159(5):863-870, 2014). The genomes of the twovariants are co-linear and share an overall sequence identity of 90%.(Id.). Even the highly conserved glycoproteins gH, gB, gN, and gO aredistinguishably different in sequence, and consistently different(conserved across isolates). The two variants also appear to exhibitslightly different epidemiology and disease associations. (Id.).Nonetheless, the same glycoproteins present in other HHV family membersare encoded by the HHV-6 and HHV-7 genomes.

HHV-6 encodes many of the same surface glycoproteins as previouslymentioned for other HHV family members, including gB, gH, gL, and gM,for which relatively conserved homologs have been identified in allknown mammalian herpesviruses. (Santoro et al., J. Biol. Chem.,278:25964-25969, 2003; and Dockrell, D. H., J. Med. Microbiol., 52:5-18,2003). As with other family members, glycoproteins gH and gL playprominent roles in HHV-6 membrane fusion based on inhibitory activitiesof specific antibodies. (Foa-Tomasi et al., J. Virol., 65:4124-4129,1991; Gompels et al., J. Virol., 65:2393-2401, 1991; Liu et al.,Virology, 197:12-22, 1993; and Qian et al., Virology, 194:380-386,1993). As in other herpesviruses, these glycoproteins form aheterodimeric complex, with gL being required for correct folding,intracellular maturation, and surface expression of gH. (Anderson etal., J. Gen. Virol., 80:1485-1494, 1999; Hutchinson et al., J. Virol.,66:2240-2250, 1992; Liu et al., J. Gen. Virol., 74:1847-1857, 1993; andRoop et al., J. Virol., 67:2285-2297, 1993). HHV-6 glycoprotein gB,known to be the most highly conserved glycoprotein among herpesviruses,and glycoprotein gp82-gp105 (only found in HHV-6 and the relatedβ-herpesvirus, HHV-7) are important for the fusion/entry process.(Takeda et al., Virology, 222:176-183, 1996; Pfeiffer et al., J. Virol.,69:3490-3500, 1995; and Pfeiffer et al., J. Virol., 67:4611-4620, 1993).

The antigenic compositions and methods of this application typicallyinvolve two or more HHV proteins involved in mediating HHV binding,fusion, and entry into host cells. In certain embodiments, two or moreHHV-6 and HHV-7 proteins disclosed herein are combined in an antigeniccomposition. The two or more HHV-6 and HHV-7 proteins can beadministered simultaneously or separately to induce an immune responseor to treat or prevent an HHV-6 or HHV-7 infection in a subject. Incertain embodiments, the antigenic composition (or method ofadministration) comprises two or more of the following HHV-6 and HHV-7polypeptides (or nucleic acids encoding the same): gB, gH, and gL. Insome embodiments, the gB polypeptide is monomeric, dimeric, or trimeric.In some embodiments, the gH and gL polypeptides are monomeric, dimeric,trimeric, or tetrameric. Typically, gH and gL form a gH/gL heterodimer.

In certain embodiments, the two or more HHV-6 or HHV-7 proteins (ornucleic acids encoding the same) comprise a monomeric or multimeric gBand a monomeric or multimeric gH/gL heterodimer. In certain embodiments,the gB is monomeric, dimeric or trimeric and the gH/gL heterodimer ismonomeric or trimeric. In certain embodiments, the gB is trimeric andthe gH/gL heterodimer is monomeric. In certain embodiments, the gB istrimeric and the gH/gL heterodimer is trimeric. In certain embodiments,the gB is monomeric and the gH/gL heterodimer is monomeric or trimeric.In certain embodiments, the HHV-6 or HHV-7 gB, gH, and gL polypeptidesform a protein complex when mixed together. In certain embodiments, theHHV-6 or HHV-7 gB, gH, and gL polypeptides are not administered as aprotein complex comprising the gB, gH, and gL polypeptides. For example,the gB can be administered separately from the gH and/or gL oradministered with the gH and gL but not as a protein complex.

The amino acid sequence of HHV-6A gH is (SEQ ID NO: 26):

MLLRLWVFVL LTPCYGWRPL NISNSSHCRN GNFENPIVRP GFITFNFYTK  50NDTRIYQVPK CLLGSDITYH LFDAINTTES LTNYEKRVIR FYEPPMNDIL 100RLSPVPSVKQ FNLDRSIQPQ VVYSLNMYPS QGIYYVRVVE VRQMQYDNVS 150CKLPNSLKEL IFPVQVRCAK ITRYVGEDIY THFFTPDFMI LYIQNPAGDL 200TMMYGNTTSI NFKAPYKKSS FIFKQTLTDD LLLIVEKDVI DVQYRFISDA 250TFVDETLNDV DEVEALLLKF NNLGIQTLLR GDCKKPNYAG IPQMMFLYGI 300VHFSYSTKNT GPMPVLRVLK THENLLSIDS FVNRCVNVSE GTLQYPKMKE 350FLKYEPSDYS YITKNKSISV STLLTYLATA YESNVTISKY KWTDIANTLQ 400NIYEKHMFFT NLTFSDRETL FMLAEIANII PTDERMQRHM QLLIGNLCNP 450VEIVSWARML TADRAPNLEN IYSPCASPVR RDVTNSFLKT VLTYASLDRY 500RSDMMEMLSV YRPPNMERVA AIQCLSPSEP AASLTLPNVT FVISPSYVIK 550GVSLTITTTI VATSIIITAI PLNSTCVSTN YKYAGQDLLV LRNISSQTCE 600FCQSVVMEYD DIDGPLQYIY IKNIDELKTL TDPNNNLLVP NTRTHYLLLA 650KNGSVFEMSE VGIDIDQVSI ILVIIYILIA IIALFGLYRL IRLC

The amino acid sequence of HHV-6B gH is (SEQ ID NO: 27):

MLFRLWVFVL LTPCYSWRPW TISDESHCKN GNSENPIVRP GFITFNFYTK  50NDTRIYQVPK CLLGSDITYH LFDAINTTES LTNYEKRVIR FYEPPMNDIL 100RLSTVPAVKQ FNLDHSIQPQ IVYSLNLYPS HGIYYIRVVE VRQMQYDNVS 150CKLPNSLNEL IFPVQVRCAK ITRYAGENIY THFFTPDFMI LYIQNPAGDL 200TMMYGNTTDI NFKAPYRKSS FIFKQTLTDD LLLIVEKDVV DEEYRFISDA 250TFVDETLDDV DEVEALLLKF NNLGIQTLLR GDCKKPDYAG IPQMMFLYGI 300VHFSYSTKNT GPMPVLRVLK THENLLSIDS FVNRCVNVSE GTIQYPKMKE 350FLKYEPSDYS YITKNKSIPV STLLTYLATA YETNVTISRY KWSDIANTLQ 400KIYEKHMFFT NLIFSDRETL FMLAEIANFI PADERMQRHM QLLIGNLCNP 450VEIVSWAHML TADKAPNLEN IYSPCASPVR RDVTNSFVKT VLTYASLDRY 500RSDMMEMLSV YRPPDMARVA AIQCLSPSEP AASLPLPNVT FVISPSYVIK 550GVSLTITTTI VATSIIITAI PLNSTCVSTN YKYAGQDLLV LRNISSQTCE 600FCQSVVMEYD DIDGPLQYIY IKNIDELKTL TDPNNNLLVP NTRTHYLLLA 650KNGSVFEMSE VGIDIDQVSI ILVIIYVLIA IIALFGLYRL IRLC

The amino acid sequence of HHV-6A gL is (SEQ ID NO: 28):

MELLLFVMSL ILLTFSKAIP LFNHNSFYFE KLDDCIAAVI NCTKSEVPLL  50LEPIYQPPAY NEDVMSILLQ PPTKKKPFSR IMVTDEFLSD FLLLQDNPEQ 100LRTLFALIRD PESRDNWLNF FNGFQTCSPS VGITTCIRDN CRKYSPEKIT 150YVNNFFVDNI AGLEFNISEN TDSFYSNIGF LLYLENPAKG VTKIIPFPFN 200SLTLFDTILN CLKYFHLKTG VELDLLKHME TYNSKLPFRS SRPTILIRNT 250

The amino acid sequence of HHV-6B gL is (SEQ ID NO: 29):

MELLLFVMSL ILLTFSKAMP LFDHNSFYFE KLDDCIAAVI NCTRSEVPLL  50LEPIYQPPVY NEDVMSILLK PPTKKKPFSR IMVTNEFLSD FLLLQDNPEQ 100LRTLFALIGD PESRDNWLNF FNGFQTCSPS VGITTCISDN CRKYLPERIT 150YVNNFFVDNI AGLEFNISEN TDSFYSNIGF LLYLENPATG ITKIIRFPFN 200SLTLFDTILN CLKYFHLKTG VEFDLLKQME AYNSKLPFRS SRPTILIRNT 250

The amino acid sequence of HHV-6A gB is (SEQ ID NO: 30):

MSKMAVLFLA VFLMNSVLMI YCDPDHYIRA GYNHKYPFRI CSIAKGTDLM  50RFDRDISCSP YKSNAKMSEG FFIIYKTNIE TYTFPVRTYK KELTFQSSYR 100DVGVVYFLDR TVMGLAMPVY EANLVNSHAQ CYSAVAMKRP DGTVFSAFHE 150DNNKNNTLNL FPLNFKSITN KRFITTKEPY FARGPLWLYS TSTSLNCIVT 200EATAKAKYPF SYFALTTGEI VEGSPFFNGS NGKHFAEPLE KLTILENYTM 250IEDLMNGMNG ATTLVRKIAF LEKADTLFSW EIKEENESVC MLKHWTTVTH 300GLRAETNETY HFISKELTAA FVAPKESLNL TDPKQTCIKN EFEKIINEVY 350MSDYNDTYSM NGSYQIFKTT GDLILIWQPL VQKSLMFLEQ GSEKIRRRRD 400VGDVKSRHDI LYVQLQYLYD TLKDYINDAL GNLAESWCLD QKRTITMLHE 450LSKISPSSIV SEVYGRPISA QLHGDVLAIS KCIEVNQSSV QLHKSMRVVD 500AKGVRSETMC YNRPLVTFSF VNSTPEVVPG QLGLDNEILL GDHRTEECEI 550PSTKIFLSGN HAHVYTDYTH TNSTPIEDIE VLDAFIRLKI DPLENADFKV 600LDLYSPDELS RANVFDLENI LREYNSYKSA LYTIEAKIAT NTPSYVNGIN 650SFLQGLGAIG TGLGSVISVT AGALGDIVGG VVSFLKNPFG GGLMLILAIV 700VVVIIIVVFV RQRHVLSKPI DMMFPYATNP VTTVSSVTGT TVVKTPSVKD 750VDGGTSVAVS EKEEGMADVS GQVSDDEYSQ EDALKMLKAI KSLDESYRRK 800PSSSESHASK PSLIDRIRYR GYKSVNVEEA

The amino acid sequence of HHV-6B gB is (SEQ ID NO: 31):

MSKMRVLFLA VFLMNSVLMI YCDSDDYIRA GYNHKYPFRI CSIAKGTDLM  50RFDRDISCSP YKSNAKMSEG FFIIYKTNIE TYTFPVRTYK NELTFPTSYR 100DVGVVYFLDR TVMGLAMPVY EANLVNSRAQ CYSAVAIKRP DGTVFSAYHE 150DNNKNETLEL FPLNFKSVTN KRFITTKEPY FARGPLWLYS TSTSLNCIVT 200EATAKAKYPF SYFALTTGEI VEGSPFFDGS NGKHFAEPLE KLTILENYTM 250IEDLMNGMNG ATTLVRKIAF LEKGDTLFSW EIKEENESVC MLKHWTTVTH 300GLRAETDETY HFISKELTAA FVASKESLNL TDPKQTCIKN EFEKIITDVY 350MSDYNDAYSM NGSYQIFKTT GDLILIWQPL VQKSLMVLEQ GSVNLRRRRD 400LVDVKSRHDI LYVQLQYLYD TLKDYINDAL GNLAESWCLD QKRTITMLHE 450LSKISPSSIV SEVYGRPISA QLHGDVLAIS KCIEVNQSSV QLYKSMRVVD 500AKGVRSETMC YNRPLVTFSF VNSTPEVVLG QLGLDNEILL GDHRTEECEI 550PSTKIFLSGN HAHVYTDYTH TNSTPIEDIE VLDAFIRLKI DPLENADFKL 600LDLYSPDELS RANVFDLENI LREYNSYKSA LYTIEAKIAT NTPSYVNGIN 650SFLQGLGAIG TGLGSVISVT AGALGDIVGG VVSFLKNPFG GGLMLILAIV 700VVVIIIVVFV RQKHVLSKPI DMMFPYATNP VTTVSSVTGT TVVKTPSVKD 750ADGGTSVAVS EKEEGMADVS GQISGDEYSQ EDALKMLKAI KSLDESYRRK 800PSSSESHASK PSLIDRIRYR GYKSVNVEEA

The amino acid sequence of HHV-7 gH is (SEQ ID NO: 32):

MYFYINSLLL IVSINGWKHW NILNSSICVN EKTNQTIIQP GLITFNFHDY  50NETRVYQIPK CLFGYTFVSN LFDSVNFDES FDQYKHRITR FFNPSTEKAV 100KIYAQKFQTN IKPVSHTKTI TVSFLPLFYE KDVYFANVSE IRKLYYNQYI 150CTLSNGLTDY LFPITERCVM RHYNYLNTVF MLALTPSFFI ISVETGMDDV 200VFIFGNVSRI FFKAPFRKSS FIYRQTVSDD LLLITKKITI ERFYPFLKID 250FLDDIWKQNY DISFLIAKFN KLATVYIMEG FCGKPVNKDT FHLMFLFGLT 300HFLYSTRGDG LLPLLEILNT HQSIITMGRF LEKCFKMTKS HLLYPEMEKL 350QNFQLVDYSY ITSDLTIPIS AKLAFLSLAD GRIVTVPQNK WKEIENNIET 400LYEKHKLFTN LTQPERANLF LLSEIGNSLV FQEKIKRKIH VLLASLCNPL 450EMYFWTHMLD NVMDIETMFS PCATATRKDL TQRVVNNILS YKNLDAYTNK 500VMNTLSVYRK KRLDMFKSIS CVSNEQAAFL TLPNITYTIS SKYILAGTSF 550SVISTVISTT IIITVVPLNS TCTPTNYKYS VKNIKPIYNI SSHDCVFCES 600LVVEYDDIDG IIQFVYIMDD KQLLKLIDPD TNFIDVNPRT HYLLFLRNGS 650VFEITALDLK SSQVSIMLVL LYLIIIIIVL FGIYHVFRLF

The amino acid sequence of HHV-7 gL is (SEQ ID NO: 33):

MKTNIFFIFL ISILNQIYAL FNNSYYSNLE QECIKNILNC TQSKTLSLLE  50PIDQAPIPKS DIISRLLYHT PYISRRDQVL IDEDFLETFY LLYNNPNQLH 100TLLSLIKDSE SGHNWLGFLN NFERCLSDNT LLTCRDNVCK SYSYEKLKFT 150GNIFVENIIG FEFNIPSNMI NFNMSILIYL ENEETRTQRI VRIDHHGINV 200FDALLNCLRY FSRYYNFSFP LIQEMEKYNE VLPFRSEFSN LLIRTY

The amino acid sequence of HHV-7 gB is (SEQ ID NO: 34):

MKILFLSVFI TFSLQLSLQT EADFVMTGHN QHLPFRICSI ATGTDLVRFD  50REVSCASYGS NIKTTEGILI IYKTKIEAHT FSVRTFKKEL TFQTTYRDVG 100TVYFLDRTVT TLPMPIEEVH MVNTEARCLS SISVKRSEEE EYVAYHKDEY 150VNKTLDLIPL NFKSDTVRRY ITTKEPFLRN GPLWFYSTST SINCIVTDCI 200AKTKYPFDFF ALSTGETVEG SPFYNGINSK TFNEPTEKIL FRNNYTMLKT 250FDDGSKGNFV TLTKMAFLEK GNTIFSWEVQ NEESSICLLK HWMTIPHALR 300AENANSFHFI AQELTASFVT GKSNYTLSDS KYNCINSNYT SILDEIYQTQ 350YNNSHDKNGS YEIFKTEGDL ILIWQPLIQR KLTVLENFSN ASRKRRKREL 400ETNKDIVYVQ LQYLYDTLKD YINTALGKLA EAWCLNQKRT ITVLHELSKI 450SPSGIISAVY GKPMSAKLIG DVLAVSKCIE VNQTSVQLHK SMRLTKDSSY 500DALRCYSRPL LTYSFANSSK ETYLGQLGLD NEILLGNHRT EECEQSNTKI 550FLSGKFAHIF KDYTYVNSSL ITEIEALDAF VDLNIDPLEN ADFTLLELYT 600KDELSKANVF DLETILREYN SYKSALHHIE TKIATVTPTY IGGIDTFFKG 650LGALGLGLGA VLGVTAGALG DVVNGVFSFL KNPFGGALTI LLTLGVIGLV 700IFLFLRHKRL AQTPIDILFP YTSKSTNSVL QATQSVQAQV KEPLDSSPPY 750LKTNKDTEPQ GDDITHTNEY SQVEALKMLK AIKLLDESYK KAEIAEAKKS 800QRPSLLERIQ YRGYQKLSTE EL

Alphaherpesviruses: Type 1 Human Herpes Virus (HHV-1), Type 2 HumanHerpes Virus (HHV-2), & Varicella-Zoster Virus (VZV, HHV-3)

HHV-1, or herpes simplex virus-1 (HSV-1), causes oral herpes, HHV-2, orherpes simplex virus-1 (HSV-2) causes genital herpes, and HHV-3, or VZV,causes chickenpox and shingles. Each of these viruses belong to thealphaherpesvirus sub-family of the herpesvirus family and areneurotropic viruses. VZV infects nearly all humans and primary infectioncauses chickenpox (varicella). Latent VZV resides most commonly in thecranial nerve ganglia, dorsal root ganglia, and autonomic ganglia alongthe neuroaxis. The viruses of this sub-family and reactivatespontaneously, resulting in shingles (zoster). Zoster skin lesionsusually last more than a week, but in some individuals infection canlead to chronic pain or postherpetic neuralgia (PHN, pain that lastsmore than three months) as well as vasculopathy can occur in about 40%of patients older than 60 years of age. Zoster paresis (zoster withlower motor neuron type weakness) may also occur in the arms, legs,diaphragm, and/or abdominal muscles. Pathological features of zosterinclude inflammation and haemorrhagic necrosis with associated neuritis,localized leptomeningitis, unilateral segmental poliomyelitis, anddegeneration of related motor and sensory roots. Demyelination is seenin areas with mononuclear cell (MNC) infiltration and microglialproliferation. Intranuclear inclusions, viral antigen, and herpesvirusparticles have been found in acutely infected ganglia. Vasculopathy (orstroke) can be caused by productive virus infection of cerebral arteriesand is referred to as granulomatous angiitis, VZVvasculitis/encephalitis, post-varicella arteriopathy, and herpes zosterophthalmicus with delayed contralateral hemiparesis. Symptoms caninclude fever, altered mental status, headaches, and focal neurologicaldeficits. (Gilden et al., Neuropathol. Appl. Neurobiol., 37(5):441-463,2012). Other serious complications of VZV infection include Mollaret'smeningitis, zoster multiplex, muelitis, herpes ophthalmicus (zoster sineherpete), and Ramsay Hunt Syndrome. Studies have indicated an increasedrisk of stroke after zoster. (Kang et al., Stroke, 40(11):3443-3448,2009; and Lin et al., Neurology, 74(10):792-797, 2010). Acute infectionsof VZV can lead to mengitis, meningoencephalitis, meningoradiculitis,and cerebellitis. (Habib et al., J. Neurovirol., 15(2):206-208, 2009;Klein et al., Scan. J. Infect. Dis., 42(8):631-633, 2010; Gunson et al.,J. Clin. Virol., 50(3):191-193, 2011; and Moses et al., Lancet Neurol.,5(11):984-988, 2006).

The VZV genome was the first herpesvirus genome to be completelysequenced, in 1986. The VZV genome is exceedingly stable, yielding onlythree point mutations in over 1200 passages. (Liu et al., Arch. Virol.,153(10):1943-7, 2008). Infection proceeds from Langerhans cells toresident T cells near draining lymph nodes. T cells are induced toexpress skin-homing factors that transport the virus-loaded T cell tothe dermis where fibroblasts and keratinocytes are exposed to infectionand produce proinflammatory cytokines yielding varicella. (Taylor etal., J. Virol., 79(17):11501-6, 2005; and Huch et al., J. Virol.,84(8):4060-72, 2010). VZV triggers apoptosis in several cell types,including kidney cells, melanoma cells, fibroblasts, and others.(Pugazhenthi et al., J. Virol., 83(18):9273-82, 2009).

Various pharmaceutical treatments are available for VZV infections,including acyclovir for the chicken pox, famciclovir, valaciclovir forthe shingles, zoster-immune globulin (ZIG), and vidarabine. VZV immuneglobulin is also a treatment. (Centers for Disease Control andPrevention (CDC), March 2012, “FDA approval of an extended period foradministering VariZIG for postexposure prophylaxis of varicella,” Morb.Mortal. Wkly. Rep., 61(12):212, PMID 2245612).

VZV and HSV-1/HSV-2 produce the known envelope glycoproteins gB, gH andgL, gM, gN, corresponding to the same or similar glycoproteins andassociated protein functions found in other HHV species. Although thereis no equivalent of the HHV-1/HHV-2 glycoprotein gD in VZV, glycoproteingE of VZV performs a similar function. (Cohen, J. I., Curr. Top.Microbiol. Immunol., 342:1-14, 2010). Expression of gB, gH, and gL isnecessary and sufficient to induce membrane fusion, prior to virionentry into a host cell, allowing the nucleocapsid to gain access to thecytoplasm. Other accessory glycoproteins similar to gp42, gD, gO, orUL128-130, are not needed for fusion. (Eisenberg et al., Viruses,4:800-832, 2012; Vleck et al., Proc. Natl. Acad. Sci. USA, 108:18412-7,2011; and Oliver et al., Proc. Natl. Acad. Sci. USA, 110:1911-6, 2013).

At least two cell proteins, insulin-degrading enzyme (IDE), andmyelin-associated glycoprotein (MAG), are thought to function asreceptors for VZV entry into host cells; however, other studiesimplicate the αV subunit of integrins as playing a role in membranefusion for VZV. (Yang et al., J. Virol., 90(16):7567-78, 2016).

The antigenic compositions and methods of this application typicallyinvolve two or more HHV proteins involved in mediating HHV binding,fusion, and entry into host cells. In certain embodiments, two or moreVZV proteins disclosed herein are combined in an antigenic composition.The two or more VZV proteins can be administered simultaneously orseparately to induce an immune response or to treat or prevent a VZVinfection in a subject. In certain embodiments, the antigeniccomposition (or method of administration) comprises two or more of thefollowing VZV polypeptides (or nucleic acids encoding the same): gB, gH,and gL. In some embodiments, the gB polypeptide is monomeric, dimeric,or trimeric. In some embodiments, the gH and gL polypeptides aremonomeric, dimeric, trimeric, or tetrameric. Typically, gH and gL form agH/gL heterodimer.

In certain embodiments, the two or more VZV proteins (or nucleic acidsencoding the same) comprise a monomeric or multimeric gB and a monomericor multimeric gH/gL heterodimer. In certain embodiments, the gB ismonomeric, dimeric or trimeric and the gH/gL heterodimer is monomeric ortrimeric. In certain embodiments, the gB is monomeric and the gH/gLheterodimer is monomeric. In certain embodiments, the gB is trimeric andthe gH/gL heterodimer is trimeric. In certain embodiments, the gB istrimeric and the gH/gL heterodimer is monomeric or trimeric. In certainembodiments, the VZV gB, gH, and gL polypeptides form a protein complexwhen mixed together. In certain embodiments, the VZV gB, gH, and gLpolypeptides are not administered as a protein complex comprising thegB, gH, and gL polypeptides. For example, the gB can be administeredseparately from the gH and/or gL or administered with the gH and gL butnot as a protein complex. In certain embodiments, the two or more VZVproteins further comprise one or more of the following glycoproteins:gI, gC, and/or gE, which can be monomeric or multimeric (e.g., dimeric,trimeric, or tetrameric).

The amino acid sequence of VZV gH is (SEQ ID NO: 35):

MFALVLAVVI LPLWTTANKS YVTPTPATRS IGHMSALLRE YSDRNMSLKL  50EAFYPTGFDE ELIKSLHWGN DRKHVFLVIV KVNPTTHEGD VGLVIFPKYL 100LSPYHFKAEH RAPFPAGRFG FLSHPVTPDV SFFDSSFAPY LTTQHLVAFT 150TFPPNPLVWH LERAETAATA ERPFGVSLLP ARPTVPKNTI LEHKAHFATW 200DALARHTFFS AEAIITNSTL RIHVPLFGSV WPIRYWATGS VLLTSDSGRV 250EVNIGVGFMS SLISLSSGPP IELIVVPHTV KLNAVTSDTT WFQLNPPGPD 300PGPSYRVYLL GRGLDMNFSK HATVDICAYP EESLDYRYHL SMAHTEALRM 350TTKADQHDIN EESYYHIAAR IATSIFALSE MGRTTEYFLL DEIVDVQYQL 400KFLNYILMRI GAGAHPNTIS GTSDLIFADP SQLHDELSLL FGQVKPANVD 450YFISYDEARD QLKTAYALSR GQDHVNALSL ARRVIMSIYK GLLVKQNLNA 500TERQALFFAS MILLNFREGL ENSSRVLDGR TTLLLMTSMC TAAHATQAAL 550NIQEGLAYLN PSKHMFTIPN VYSPCMGSLR TDLTEEIHVM NLLSAIPTRP 600GLNEVLHTQL DESEIFDAAF KTMMIFTTWT AKDLHILHTH VPEVFTCQDA 650AARNGEYVLI LPAVQGHSYV ITRNKPQRGL VYSLADVDVY NPISVVYLSR 700DTCVSEHGVI ETVALPHPDN LKECLYCGSV FLRYLTTGAI MDIIIIDSKD 750TERQLAAMGN STIPPFNPDM HGDDSKAVLL FPNGTVVTLL GFERRQAIRM 800SGQYLGASLG GAFLAVVGFG IIGWMLCGNS RLREYNKIPL T

The amino acid sequence of VZV gL is (SEQ ID NO: 36):

MASHKWLLQI VFLKTITIAY CLHLQDDTPL FFGAKPLSDV SLIITEPCVS  50SVYEAWDYAA PPVSNLSEAL SGIVVKTKCP VPEVILWFKD KQMAYWTNPY 100VTLKGLAQSV GEEHKSGDIR DALLDALSGV WVDSTPSSTN IPENGCVWGA 150 DRLFQRVCQ

The amino acid sequence of VZV gB is (SEQ ID NO: 37):

MSPCGYYSKW RNRDRPEYRR NLRFRRFFSS IHPNAAAGSG FNGPGVFITS  50VTGVWLCFLC IFSMFVTAVV SVSPSSFYES LQVEPTQSED ITRSAHLGDG 100DEIREAIHKS QDAETKPTFY VCPPPTGSTI VRLEPTRTCP DYHLGKNFTE 150GIAVVYKENI AAYKFKATVY YKDVIVSTAW AGSSYTQITN RYADRVPIPV 200SEITDTIDKF GKCSSKATYV RNNHKVEAFN EDKNPQDMPL IASKYNSVGS 250KAWHTTNDTY MVAGTPGTYR TGTSVNCIIE EVEARSIFPY DSFGLSTGDI 300IYMSPFFGLR DGAYREHSNY AMDRFHQFEG YRQRDLDTRA LLEPAARNFL 350VTPHLTVGWN WKPKRTEVCS LVKWREVEDV VRDEYAHNFR FTMKTLSTTF 400ISETNEFNLN QIHLSQCVKE EARAIINRIY TTRYNSSHVR TGDIQTYLAR 450GGFVVVFQPL LSNSLARLYL QELVRENTNH SPQKHPTRNT RSRRSVPVEL 500RANRTITTTS SVEFAMLQFT YDHIQEHVNE MLARISSSWC QLQNRERALW 550SGLFPINPSA LASTILDQRV KARILGDVIS VSNCPELGSD TRIILQNSMR 600VSGSTTRCYS RPLISIVSLN GSGTVEGQLG TDNELIMSRD LLEPCVANHK 650RYFLFGHHYV YYEDYRYVRE IAVHDVGMIS TYVDLNLTLL KDREFMPLQV 700YTRDELRDTG LLDYSEIQRR NQMHSLRFYD IDKVVQYDSG TAIMQGMAQF 750FQGLGTAGQA VGHVVLGATG ALLSTVHGFT TFLSNPFGAL AVGLLVLAGL 800VAAFFAYRYV LKLKTSPMKA LYPLTTKGLK QLPEGMDPFA EKPNATDTPI 850EEIGDSQNTE PSVNSGFDPD KFREAQEMIK YMTLVSAAER QESKARKKNK 900TSALLTSRLT GLALRNRRGY SRVRTENVTG V

The amino acid sequence of VZV gI is (SEQ ID NO: 38):

MFLIQCLISA VIFYIQVTNA LIFKGDHVSL QVNSSLTSIL IPMQNDNYTE  50IKGQLVFIGE QLPTGTNYSG TLELLYADTV AFCFRSVQVI RYDGCPRIRT 100SAFISCRYKH SWHYGNSTDR ISTEPDAGVM LKITKPGIND AGVYVLLVRL 150DHSRSTDGFI LGVNVYTAGS HHNIHGVIYT SPSLQNGYST RALFQQARLC 200DLPATPKGSG TSLFQHMLDL RAGKSLEDNP WLHEDVVTTE TKSVVKEGIE 250NHVYPTDMST LPEKSLNDPP ENLLIIIPIV ASVMILTAMV IVIVISVKRR 300RIKKHPIYRP NTKTRRGIQN ATPESDVMLE AAIAQLATIR EESPPHSVVN 350 PFVK

The amino acid sequence of VZV gC is (SEQ ID NO: 39):

MKRIQINLIL TIACIQLSTE SQPTPVSITE LYTSAATRKP DPAVAPTSAA  50SRKPDPAVAP TSAASRKPDP AVAPTSAASR KPDPAVAPTS AATRKPDPAV 100APTSAASRKP DPAVAPTSAA TRKPDPAVAP TSAASRKPDP AANTQHSQPP 150FLYENIQCVH GGIQSIPYFH TFIMPCYMRL TTGQQAAFKQ QQKTYEQYSL 200DPEGSNITRW KSLIRPDLHI EVWFTRHLID PHRQLGNALI RMPDLPVMLY 250SNSADLNLIN NPEIFTHAKE NYVIPDVKTT SDFSVTILSM DATTEGTYIW 300RVVNTKTKNV ISEHSITVTT YYRPNITVVG DPVLTGQTYA AYCNVSKYYP 350PHSVRVRWTS RFGNIGKNFI TDAIQEYANG LFSYVSAVRI PQQKQMDYPP 400PAIQCNVLWI RDGVSNMKYS AVVTPDVYPF PNVSIGIIDG HIVCTAKCVP 450RGVVHFVWWV NDSPINHENS EITGVCDQNK RFVNMQSSCP TSELDGPITY 500SCHLDGYPKK FPPFSAVYTY DASTYATTFS VVAVIIGVIS ILGTLGLIAV 550 IATLCIRCCS

The amino acid sequence of VZV gE is (SEQ ID NO: 40):

MGTVNKPVVG VLMGFGIITG TLRITNPVRA SVLRYDDFHT DEDKLDTNSV  50YEPYYHSDHA ESSWVNRGES SRKAYDHNSP YIWPRNDYDG FLENAHEHHG 100VYNQGRGIDS GERLMQPTQM SAQEDLGDDT GIHVIPTLNG DDRHKIVNVD 150QRQYGDVFKG DLNPKPQGQR LIEVSVEENH PFTLRAPIQR IYGVRYTETW 200SFLPSLTCTG DAAPAIQHIC LKHTTCFQDV VVDVDCAENT KEDQLAEISY 250RFQGKKEADQ PWIVVNTSTL FDELELDPPE IEPGVLKVLR TEKQYLGVYI 300WNMRGSDGTS TYATFLVTWK GDEKTRNPTP AVTPQPRGAE FHMWNYHSHV 350FSVGDTFSLA MHLQYKIHEA PFDLLLEWLY VPIDPTCQPM RLYSTCLYHP 400NAPQCLSHMN SGCTFTSPHL AQRVASTVYQ NCEHADNYTA YCLGISHMEP 450SFGLILHDGG TTLKFVDTPE SLSGLYVFVV YFNGHVEAVA YTVVSTVDHF 500VNAIEERGFP PTAGQPPATT KPKEITPVNP GTSPLLRYAA WTGGLAAVVL 550LCLVIFLICT AKRMRVKAYR VDKSPYNQSM YYAGLPVDDF EDSESTDTEE 600EFGNAIGGSH GGSSYTVYID KTR

The antigenic compositions and methods of this application typicallyinvolve two or more HHV proteins involved in mediating HHV binding,fusion, and entry into host cells. In certain embodiments, two or moreHSV-1 or HSV-2 proteins disclosed herein are combined in an antigeniccomposition. The two or more HSV-1 or HSV-2 proteins can be administeredsimultaneously or separately to induce an immune response or to treat orprevent an HSV-1 or HSV-2 infection in a subject. In certainembodiments, the antigenic composition (or method of administration)comprises two or more of the following HSV-1 or HSV-2 polypeptides (ornucleic acids encoding the same): gB, gH, and gL. In some embodiments,the gB polypeptide is monomeric, dimeric, or trimeric. In someembodiments, the gH and gL polypeptides are monomeric, dimeric,trimeric, or tetrameric. Typically, gH and gL form a gH/gL heterodimer.

In certain embodiments, the two or more HSV-1 or HSV-2 proteins (ornucleic acids encoding the same) comprise a monomeric or multimeric gBand a monomeric or multimeric gH/gL heterodimer. In certain embodiments,the gB is monomeric, dimeric or trimeric and the gH/gL heterodimer ismonomeric or trimeric. In certain embodiments, the gB is monomeric andthe gH/gL heterodimer is monomeric or trimeric. In certain embodiments,the gB is trimeric and the gH/gL heterodimer is monomeric. In certainembodiments, the gB is trimeric and the gH/gL heterodimer is trimeric.In certain embodiments, the HSV-1 or HSV-2 gB, gH, and gL polypeptidesform a protein complex when mixed together. In certain embodiments, theHSV-1 or HSV-2 gB, gH, and gL polypeptides are not administered as aprotein complex comprising the gB, gH, and gL polypeptides. For example,the gB can be administered separately from the gH and/or gL oradministered with the gH and gL but not as a protein complex.

In certain embodiments, the two or more HSV-1 or HSV-2 proteins furthercomprises a gD polypeptide, which can be monomeric or multimeric (e.g.,dimeric, trimeric, or tetrameric).

The amino acid sequence of HSV-1 gH is (SEQ ID NO: 41):

MGNGLWFVGV IILGAAWGQV HDWTEQTDPW FLDGLGMDRM YWRDTNTGRL  50WLPNTPDPQK PPRGFLAPPD ELNLTTASLP LLRWYEERFC FVLVTTAEFP 100RDPGQLLYIP KTYLLGRPPN ASLPAPTTVE PTAQPPPAVA PLKGLLHNPT 150ASVLLRSRAW VTFSAVPDPE ALTFPRGDNV ATASHPSGPR DTPPPRPPVG 200ARRHPTTELD ITHLHNASTT WLATRGLLRS PGRYVYFSPS ASTWPVGIWT 250TGELVLGCDA ALVRARYGRE FMGLVISMHD SPPAEVMVVP AGQTLDRVGD 300PADENPPGAL PGPPGGPRYR VFVLGSLTRA DNGSALDALR RVGGYPEEGT 350NYAQFLSRAY AEFFSGDAGA EQGPRPPLFW RLTGLLATSG FAFVNAAHAN 400GAVCLSDLLG FLAHSRALAG LAARGAAGCA ADSVFFNVSV LDPTARLQLE 450ARLQHLVAEI LEREQSLALH ALGYQLAFVL DSPSAYDAVA PSAAHLIDAL 500YAEFLGGRVV TTPVVHRALF YASAVLRQPF LAGVPSAVQR ERARRSLLIA 550SALCTSDVAA ATNADLRTAL ARADHQKTLF WLPDHFSPCA ASLRFDLDES 600VFILDALAQA TRSETPVEVL AQQTHGLAST LTRWAHYNAL IRAFVPEASH 650RCGGQSANVE PRILVPITHN ASYVVTHSPL PRGIGYKLTG VDVRRPLFLT 700YLTATCEGST RDIESKRLVR TQNQRDLGLV GAVFMRYTPA GEVMSVLLVD 750TDNTQQQIAA GPTEGAPSVF SSDVPSTALL LFPNGTVIHL LAFDTQPVAA 800IAPGFLAASA LGVVMITAAL AGILKVLRTS VPFFWRRE

The amino acid sequence of HSV-1 gL is (SEQ ID NO: 42):

MGILGWVGLI AVGVLCVRGG LPSTEYVIRS RVAREVGDIL KVPCVPLPSD  50DLDWRYETPS AINYALIDGI FLRYHCPGLD TVLWDRHAQK AYWVNPFLFV 100AGFLEDLSYP AFPANTQETE TRLALYKEIR QALDSRKQAA SHTPVKAGCV 150NFDYSRTRRC VGRQDLGPTN GTSGRTPVLP PDDEAGLQPK PLTTPPPIIA 200TSDPTPRRDA ATKSRRRRPH SRRL

The amino acid sequence of HSV-1 gB is (SEQ ID NO: 43):

MHQGAPSWGR RWFVVWALLG LTLGVLVASA APTSPGTPGV AAATQAANGG  50PATPAPPPLG AAPTGDPKPK KNKKPKNPTP PRPAGDNATV AAGHATLREH 100LRDIKAENTD ANFYVCPPPT GATVVQFEQP RRCPTRPEGQ NYTEGIAVVF 150KENIAPYKFK ATMYYKDVTV SQVWFGHRYS QFMGIFEDRA PVPFEEVIDK 200INAKGVCRST AKYVRNNLET TAFHRDDHET DMELKPANAA TRTSRGWHTT 250DLKYNPSRVE AFHRYGTTVN CIVEEVDARS VYPYDEFVLA TGDFVYMSPF 300YGYREGSHTE HTTYAADRFK QVDGFYARDL TTKARATAPT TRNLLTTPKF 350TVAWDWVPKR PSVCTMTKWQ EVDEMLRSEY GGSFRFSSDA ISTTFTTNLT 400EYPLSRVDLG DCIGKDARDA MDRIFARRYN ATHIKVGQPQ YYQANGGFLI 450AYQPLLSNTL AELYVREHLR EQSRKPPNPT PPPPGASANA SVERIKTTSS 500IEFARLQFTY NHIQRHVNDM LGRVAIAWCE LQNHELTLWN EARKLNPNAI 550ASVTVGRRVS ARMLGDVMAV STCVPVAADN VIVQNSMRIS SRPGACYSRP 600LVSFRYEDQG PLVEGQLGEN NELRLTRDAI EPCTVGHRRY FTFGGGYVYF 650EEYAYSHQLS RADITTVSTF IDLNITMLED HEFVPLEVYT RHEIKDSGLL 700DYTEVQRRNQ LHDLRFADID TVIHADANAA MFAGLGAFFE GMGDLGRAVG 750KVVMGIVGGV VSAVSGVSSF MSNPFGALAV GLLVLAGLAA AFFAFRYVMR 800LQSNPMKALY PLTTKELKNP TNPDASGEGE EGGDFDEAKL AEAREMIRYM 850ALVSAMERTE HKAKKKGTSA LLSAKVTDMV MRKRRNTNYT QVPNKDGDAD 900 EDDL

The amino acid sequence of HSV-1 gD is (SEQ ID NO: 44):

MGGAAARLGA VILFVVIVGL HGVRGKYALA DASLKMADPN RFRGKDLPVP  50DRLTDPPGVR RVYHIQAGLP DPFQPPSLPI TVYYAVLERA CRSVLLNAPS 100EAPQIVRGGS EDVRKQPYNL TIAWFRMGGN CAIPITVMEY TECSYNKSLG 150ACPIRTQPRW NYYDSFSAVS EDNLGFLMHA PAFETAGTYL RLVKINDWTE 200ITQFILEHRA KGSCKYALPL RIPPSACLSP QAYQQGVTVD SIGMLPRFIP 250ENQRIVAVYS LKIAGWHGPK APYTSTLLPP ELSETPNATQ PELAPEDPED 300SALLEDPVGT VAPQIPPNWH IPSIQDAATP YHPPATPNNM GLIAGAVGGS 350LLAALVICGI VYWMRRRTQK GPKRIRLPHI REDDQPSSHQ PLFY

The amino acid sequence of HSV-2 gH is (SEQ ID NO: 45):

MGPGLWVVMG VLVGVAGGHD TYWTEQIDPW FLHGLGLART YWRDTNTGRL  50WLPNTPDASD PQRGRLAPPG ELNLTTASVP MLRWYAERFC FVLVTTAEFP 100RDPGQLLYIP KTYLLGRPRN ASLPELPEAG PTSRPPAEVT QLKGLSHNPG 150ASALLRSRAW VTFAAAPDRE GLTFPRGDDG ATERHPDGRR NAPPPGPPAG 200APRHPTTNLS IAHLHNASVT WLAARGLLRT PGRYVYLSPS ASTWPVGVWT 250TGGLAFGCDA ALVRARYGKG FMGLVISMRD SPPAEIIVVP ADKTLARVGN 300PTDENAPAVL PGPPAGPRYR VFVLGAPTPA DNGSALDALR RVAGYPEEST 350NYAQYMSRAY AEFLGEDPGS GTDARPSLFW RLAGLLASSG FAFINAAHAH 400DAIRLSDLLG FLAHSRVLAG LAARGAAGCA ADSVFLNVSV LDPAARLRLE 450ARLGHLVAAI LEREQSLAAH ALGYQLAFVL DSPAAYGAVA PSAARLIDAL 500YAEFLGGRAL TAPMVRRALF YATAVLRAPF LAGAPSAEQR ERARRGLLIT 550TALCTSDVAA ATHADLRAAL ARTDHQKNLF WLPDHFSPCA ASLRFDLAEG 600GFILDALAMA TRSDIPADVM AQQTRGVASA LTRWAHYNAL IRAFVPEATH 650QCSGPSHNAE PRILVPITHN ASYVVTHTPL PRGIGYKLTG VDVRRPLFIT 700YLTATCEGHA REIEPKRLVR TENRRDLGLV GAVFLRYTPA GEVMSVLLVD 750TDATQQQLAQ GPVAGTPNVF SSDVPSVALL LFPNGTVIHL LAFDTLPIAT 800IAPGFLAASA LGVVMITAAL AGILRVVRTC VPFLWRRE

The amino acid sequence of HSV-2 gL is (SEQ ID NO: 46):

MGFVCLFGLV VMGAWGAWGG SQATEYVLRS VIAKEVGDIL RVPCMRTPAD  50DVSWRYEAPS VIDYARIDGI FLRYHCPGLD TFLWDRHAQR AYLVNPFLFA 100AGFLEDLSHS VFPADTQETT TRRALYKEIR DALGSRKQAV SHAPVRAGCV 150NFDYSRTRRC VGRRDLRPAN TTSTWEPPVS SDDEASSQSK PLATQPPVLA 200LSNAPHGGSP RREVGAGILA SDATSHVCIA SHPGSGAGQP TRLAAGSAVQ 250RRRPRGCPPG VMFSASTTPE QPLGLSGDAT PPLPTSVPLD WAAFRRAFLI 300DDAWRPLLEP ELANPLTARL LAEYDRRCQT EEVLPPREDV FSWTRYCTPD 350DVRVVIIGQD PYHHPGQAHG LAFSVRADVP VPPSLRNVLA AVKNCYPDAR 400MSGRGCLEKW ARDGVLLLNT TLTVKRGAAA SHSKLGWDRF VGGVVRRLAA 450RRPGLVFMLW GAHAQNAIRP DPRQHYVLKF SHPSPLSKVP FGTCQHFLAA 500NRYLETRDIM PIDWSV

The amino acid sequence of HSV-2 gB is (SEQ ID NO: 47):

MRGGGLICAL VVGALVAAVA SAAPAAPAAP RASGGVAATV AANGGPASRP  50PPVPSPATTK ARKRKTKKPP KRPEATPPPD ANATVAAGHA TLRAHLREIK 100VENADAQFYV CPPPTGATVV QFEQPRRCPT RPEGQNYTEG IAVVFKENIA 150PYKFKATMYY KDVTVSQVWF GHRYSQFMGI FEDRAPVPFE EVIDKINTKG 200VCRSTAKYVR NNMETTAFHR DDHETDMELK PAKVATRTSR GWHTTDLKYN 250PSRVEAFHRY GTTVNCIVEE VDARSVYPYD EFVLATGDFV YMSPFYGYRE 300GSHTEHTSYA ADRFKQVDGF YARDLTTKAR ATSPTTRNLL TTPKFTVAWD 350WVPKRPAVCT MTKWQEVDEM LRAEYGGSFR FSSDAISTTF TTNLTEYSLS 400RVDLGDCIGR DAREAIDRMF ARKYNATHIK VGQPQYYLAT GGFLIAYQPL 450LSNTLAELYV REYMREQDRK PRNATPAPLR EAPSANASVE RIKTTSSIEF 500ARLQFTYNHI QRHVNDMLGR IAVAWCELQN HELTLWNEAR KLNPNAIASA 550TVGRRVSARM LGDVMAVSTC VPVAPDNVIV QNSMRVSSRP GTCYSRPLVS 600FRYEDQGPLI EGQLGENNEL RLTRDALEPC TVGHRRYFIF GGGYVYFEEY 650AYSHQLSRAD VTTVSTFIDL NITMLEDHEF VPLEVYTRHE IKDSGLLDYT 700EVQRRNQLHD LRFADIDTVI RADANAAMFA GLCAFFEGMG DLGRAVGKVV 750MGVVGGVVSA VSGVSSFMSN PFGALAVGLL VLAGLVAAFF AFRYVLQLQR 800NPMKALYPLT TKELKTSDPG GVGGEGEEGA EGGGFDEAKL AEAREMIRYM 850ALVSAMERTE HKARKKGTSA LLSSKVTNMV LRKRNKARYS PLHNEDEAGD 900 EDEL

The amino acid sequence of HSV-2 gD is (SEQ ID NO: 48):

MGRLTSGVGT AALLVVAVGL RVVCAKYALA DPSLKMADPN RFRGKNLPVL  50DRLTDPPGVK RVYHIQPSLE DPFQPPSIPI TVYYAVLERA CRSVLLHAPS 100EAPQIVRGAS DEARKHTYNL TIAWYRMGDN CAIPITVMEY TECPYNKSLG 150VCPIRTQPRW SYYDSFSAVS EDNLGFLMHA PAFETAGTYL RLVKINDWTE 200ITQFILEHRA RASCKYALPL RIPPAACLTS KAYQQGVTVD SIGMLPRFIP 250ENQRTVALYS LKIAGWHGPK PPYTSTLLPP ELSDTTNATQ PELVPEDPED 300SALLEDPAGT VSSQIPPNWH IPSIQDVAPH HAPAAPSNPG LIIGALAGST 350LAVLVIGGIA FWVRRRAQMA PKRLRLPHIR DDDAPPSHQP LFY

HHV Proteins. This application demonstrates that various combinations ofHHV proteins involved in mediating viral binding, fusion, and host cellentry unexpectedly induce synergistic or additive neutralizing antibodyresponses, notwithstanding concerns in the art about vaccine or immuneinterference. The HHV proteins that are combined in the antigeniccompositions disclosed herein (e.g., gB, gH, gL, gp350) or administered(simultaneously or separately) to prevent or treat a HHV infection orinduce immunity in a subject can be made using any conventionaltechnique.

For example, in certain embodiments, one or more of the HHV proteins arenaturally occurring. In other embodiments, one or more of the HHVproteins are recombinant (i.e., prepared using recombinant DNAtechniques). In certain embodiments, the recombinant HHV proteins haveone or more differences in the glycosylation pattern of the naturallyoccurring HHV proteins. In certain embodiments one or more of the HHVproteins have been modified and are not naturally occurring proteins. Incertain embodiments all of the HHV proteins have been modified and arenot naturally occurring proteins. For example, the HHV proteins may be amutated version of the wild type protein, a truncated version of thewild type protein, a multimerized protein, or a fusion protein.

In certain embodiments, the modified HHV protein is a protein that bindsto a specific target molecule and the modified HHV protein retains itsability to bind to the target molecule. In certain embodiments, thetruncated HHV protein consists of the extracellular domain of the HHVprotein or a portion thereof that retains the ability to bind to itstarget molecule, including, for example, the extracellular domain of oneor more of gB, gp350, gL, or gH. By way of example, gp350 binds to CD21(aka CR2) on the surface of B cells; gp42 binds to HLA class IImolecules; gD binds to nectin-1 (HveC, CD111) and Herpesvirus EntryMediator (HVEM); and gpK8.1A and gpK8.1B bind to a cell surface heparinsulfate molecule.

In certain embodiments, the HHV polypeptide is a variant HHV polypeptidecomprising one or more deletions, insertions, or substitutions. Forexample, gp350 and gp220 polypeptides that bind to CR2 includenaturally-occurring or synthetically programmed variant polypeptidessubstantially identical to either the gp350 or gp220 polypeptides, butwhich have an amino acid sequence different from that of gp350 or gp220because of one or more deletions, insertions or substitutions. Somegp350/220 variant sequences have already been identified by sequencingthe DNA of different strains of EBV, and are readily available to one ofordinary skill in the art (Beisel et al., J. Viriol., 1985,54(3):665-74).

Similarly, variant gH, gL, gB, gp42, gM, gN, gI, gC, gE, gD, ORF68,BMRF-2, UL128, UL130, UL131A, and gpK8.1 polypeptides can includenaturally-occurring or synthetically programmed variant polypeptidessubstantially identical to either the gH, gL, gB, gp42, gM, gN, gI, gC,gE, gD, ORF68, BMRF-2, UL128, UL130, UL131A, and gpK8.1 polypeptides,but which have an amino acid sequence different from that of gH, gL, gB,gp42, gM, gN, gI, gC, gE, gD, ORF68, BMRF-2, UL128, UL130, UL131A, andgpK8.1 because of one or more deletions, insertions or substitutions.

The variant amino acid sequence preferably is at least 60%, 65%, 70%, or80%, identical to a gp350, a gp220 polypeptide or a gH, gL, gB, gp42,gM, gN, gI, gC, gE, gD, ORF68, BMRF-2, UL128, UL130, UL131A, and gpK8.1,more preferably at least 85% identical, still more preferably at least90% identical, and most preferably at least 95% identical. The percentidentity can be determined, for example, by comparing sequenceinformation using the GAP computer program, version 6.0 described byDevereux et al. (Nucl. Acids Res., 12:387, 1984) and available from theUniversity of Wisconsin Genetics Computer Group (UWGCG). The GAP programutilizes the alignment method of Needleman and Wunsch (J. Mol. Biol.,48:443, 1970), as revised by Smith and Waterman (Adv. Appl. Math, 2:482,1981). The preferred default parameters for the GAP program include: (1)a unary comparison matrix (containing a value of 1 for identities and 0for non-identities) for nucleotides, and the weighted comparison matrixof Gribskov and Burgess, Nucl. Acids Res., 14:6745, 1986, as describedby Schwartz and Dayhoff, eds., Atlas of Protein Sequence and Structure,National Biomedical Research Foundation, pp. 353-358, 1979; (2) apenalty of 3.0 for each gap and an additional 0.10 penalty for eachsymbol in each gap; and (3) no penalty for end gaps.

Variant polypeptides can be obtained by mutation of nucleotide sequencesencoding the gp350, gp220, gH, gL, gB, gp42, gM, gN, gI, gC, gE, gD,ORF68, BMRF-2, UL128, UL130, UL131A, and/or gpK8.1 polypeptides.Alterations of the amino acid sequence can occur naturally, or beaccomplished by any of a number of conventional methods. Mutations canbe introduced at particular loci by synthesizing oligonucleotidescontaining a mutant sequence, flanked by restriction sites enablingligation to fragments of the native sequence. Following ligation, theresulting reconstructed sequence encodes an analog having the desiredamino acid insertion, substitution, or deletion.

Alternatively, oligonucleotide-directed site-specific mutagenesisprocedures can be employed to provide an altered gene whereinpredetermined codons can be altered by substitution, deletion orinsertion. Exemplary methods of making the alterations set forth aboveare disclosed by Walder et al. (Gene, 42:133, 1986); Bauer et al. (Gene37:73, 1985); Craik, (BioTechniques, Jan. 12-19, 1985); Smith et al.(Genetic Engineering: Principles and Methods, Plenum Press, 1981);Kunkel (Proc. Natl. Acad. Sci. USA, 82:488, 1985); Kunkel et al.(Methods in Enzymol., 154:367, 1987); and U.S. Pat. Nos. 4,518,584 and4,737,462, all of which are incorporated by reference.

Even though multimerizing HHV proteins has been shown to enhance theirimmunogenicity (see US2015-0174237 A1 and US2016-0303225 A1, which areincorporated by reference in their entirety), unexpected additive andsynergistic antibody responses were observed when both multimeric and/ormonomeric HHV proteins were combined. Thus, in certain embodiments, oneor more of the HHV proteins is a monomeric form of the protein. Incertain embodiments, one or more of the HHV proteins is a multimericform of the protein. In certain embodiments, one or more of the HHVproteins is monomeric and one or more of the HHV proteins is multimeric.In certain embodiments, the antigenic composition comprises a HHV gBpolypeptide that is monomeric or multimeric. In certain embodiments, themultimeric gB polypeptide is dimeric or trimeric and preferablytrimeric. In certain embodiments, the gp350 polypeptide is monomeric ormultimeric. In certain embodiments, the multimeric gp350 is dimeric,trimeric, or tetrameric and preferably tetrameric. Methods formultimerizing HHV proteins are known in the art and are discussedelsewhere in this application.

The HHV gH and gL polypeptides can be combined as individualpolypeptides in the antigenic compositions and methods described herein.In other embodiments, gH and gL form a gH/gL heterodimer. In certainembodiments, the gH/gL heterodimer is a non-covalently associatedprotein complex, such as the gH/gL protein complex that occurs naturallyand can form spontaneously under certain in vitro conditions. In otherembodiments, the gH/gL heterodimer is a fusion protein. If the HHVantigenic composition comprises the gH polypeptide and gL polypeptide inthe form of a gH/gL heterodimer, the antigenic composition furthercomprises the gB polypeptide or, for EBV, the antigenic compositionfurther comprises gB and/or the gp350 polypeptide. In certainembodiments, the gH or gL polypeptides are monomeric or multimeric. Incertain embodiments, the gH or gL polypeptide is dimeric, trimeric, ortetrameric and preferably trimeric. In certain embodiments, the gH/gLheterodimer is monomeric or multimeric. In certain embodiments, themultimeric gH/gL heterodimer is dimeric, trimeric, or tetrameric andpreferably trimeric.

Multimerizing HHV Proteins. As discussed above, the two or more HHVpolypeptides in the disclosed antigenic compositions may be multimerizedor they may be monomeric. For instance, it is known that at least the gHand gL polypeptides under some conditions form heterodimers. Further, itis known that under some conditions the gB polypeptide exists as amultimer, for instance at least as a homotrimer. (Ma, A., Virology,178(2):588-592, 1990). Further, it is known that polypeptide gBassociates with the heterodimer gH/gL to form a heterotrimer complex ofgB/gH/gL under certain circumstances. Thus, upon introducing such HHVpolypeptides into a composition, multimerization can spontaneously occurunder some circumstances.

While multimerization of the HHV polypeptides can occur spontaneouslyfor some polypeptides under appropriate conditions, others do not formmultimers under natural conditions. In some embodiments it isadvantageous to modify the two or more HHV polypeptides to formmultimers to enhance their immunogenicity. In certain embodiments, atrimeric HHV gB polypeptide is formed by expressing a modified HHV gBpolypeptide in a host cell. In the modified gB polypeptide, the furincleavage site in the extracellular domain of the gB polypeptide isreplaced by a linker sequence, as described in WO2015/089340 (alsopublished as US2016-0303225 A1, which is incorporated by reference inits entirety). FIG. 1, right panel, and FIG. 7 depict an exemplarymodified EBV and HCMV gB constructs, which form a homotrimeric gBcomplex when expressed in a host cell. In these embodiments, a linkersequence (e.g., (Gly₄Ser)₃ (SEQ ID NO: 3)) replaces the furin cleavagesite in the extracellular domain of the EBV or HCMV gB polypeptide. Anoptional leader sequence can be added to the construct to directsecretion of the recombinant polypeptide. Although these embodiments areshown with the EBV and HCMV gB polypeptides, any HHV gB sequence can besubstituted in the construct to produce the desired, modified gBpolypeptide.

In certain embodiments, multimeric HHV proteins can be synthesized usingrecombinant cloning techniques to combine oligomerization domains with aHHV polypeptide, which is optionally expressed as a fusion protein, asdescribed, for example, in WO2014/018858 (also published asUS2015-0174237 A1, which is incorporated by reference in its entirety).

Fusion Proteins. The fusion proteins used to make multimeric HHVproteins can be synthesized using standard, recombinant cloningtechniques. For instance, one strategy for making a fusion proteininvolves creating nucleic acid constructs comprising oligomerizationmotif sequences and a linker sequence separating two or more antigenssuch that the encoded fusion protein can form a dimeric, trimeric,tetrameric, hexameric, heptameric, or octameric complex from a singlenucleic acid construct. (See, WO 2014/018858, incorporated herein byreference for all purposes). This platform can be used to createmultimeric fusion proteins comprising multiple copies of a singleantigen of interest, including, for example, a gp350, gp220 polypeptide,or gB. For example, a homodimer, homotrimer, or homotetramer can becreated using two, three, or four copies of the same polypeptide with adimerization, trimerization, or tetramerization domain, respectively.When the oligomerization domains associate together, the construct willform a tetramer (if a dimerization domain is used) comprising fourcopies of the same polypeptide, a hexamer (if a trimerization domain isused) comprising six copies of the same polypeptide, or an octamercomprising eight copies of the same polypeptide (if a tetramerizationdomain is used).

Alternatively, this platform can be used to create multimeric fusionproteins comprising two or more different antigens of interest. Forexample, a heterodimer can be created with a first HHV polypeptidelinked to a second different, HHV polypeptide (or a heterotrimercomprising two or three different antigens), such as a heterodimerformed between HHV gH and gL. When the oligomerization domains associatetogether, the construct will form a tetramer (if a dimerization domainis used) that is dimeric for both the first and second HHV polypeptide,a hexamer (if a trimerization domain is used in the construct) that isdimeric for at least the first and second HHV polypeptide, or trimericfor the first, second, and third HHV polypeptide, or an octamer (if atetramerization domain is used).

In one embodiment, a trimeric protein can be formed if the originalpolypeptide is presented in monomeric form in association with thetrimerization domain. The fusion protein may optionally further comprisea third polypeptide and a second linker sequence, where the secondlinker sequence joins the second polypeptide to the third polypeptide,the first polypeptide, or the oligomerization domain. In otherembodiments, the fusion protein comprises four or more polypeptides andadditional linkers. In one embodiment, the fusion protein forms amultimeric polypeptide when expressed in a host cell. In anotherembodiment, the first and second polypeptides do not occur naturally asa multimeric protein.

In some embodiments, only a portion of the extracellular domain of eachthe HHV polypeptide is engineered into the nucleic acid constructencoding the fusion protein. Shorter polypeptides are easier to expressin larger quantities and in some embodiments only a portion of the HHVpolypeptide is needed or desired to achieve the desired immunologicaleffect, i.e., those portions of the HHV polypeptides that elicit animmune response.

The nucleic acid constructs optionally include a signal peptide-encodingnucleic acid so that the expressed fusion protein is excreted from themammalian host cell, e.g. a tissue culture comprising one or more hostcells, such as, for instance, a HeLa cells, yeast cells, insect cells,Chinese Hamster Ovary (CHO) cells, Human Embryonic Kidney (HEK) cells,COS cells, Vero cells, NS0 mouse myeloma cells, and others disclosed inthe art, such as Khan, K., Adv. Pharm. Bull., 3(2):257-263, 2013.Secretion of the fusion protein provides an easy means for proteinharvesting and purification by known methodologies.

In one embodiment, the fusion protein is formed from expression of anucleic acid construct comprising nucleic acid sequences encoding one ormore gp350 polypeptides, for example two such sequences, such that whenexpressed with a dimerization domain, such as a leucine zipperoligomerization domain, a gp350 tetramer, is formed. (See, FIG. 1, leftpanel). The gp350 nucleic acid sequence can be from any HHV genomecomprising such a sequence. Alternatively, the gp350 sequences can besubstituted with one or more other HHV polypeptide disclosed herein.

As depicted in the middle panel of FIG. 1, in another embodiment thefusion protein can be encoded by a first nucleic acid construct encodinggH and a second nucleic acid encoding gL, and a trimerization domain,such as the T4 foldon oligomerization domain, thereby yielding uponexpression, for example, a trimeric gH/gL heterodimer. The gH and gLpolypeptides can be any gH/gL polypeptide sequence found in any of theknown HHV genomes. Alternatively, in another embodiment, the gH and/orgL polypeptides can be substituted with one or more other HHVpolypeptides to form the desired HHV protein complex as describedherein.

In such embodiments, it is not necessary that the nucleic acidconstructs comprise full length HHV polypeptide sequences. The sequencescan be modified. For instance, the modified sequence can be a partial,truncated, or otherwise altered or mutated sequence. Such modifiedsequences can improve protein expression, for instance by removing thetransmembrane and intracellular domain sequences, or can elicit a morerobust immune response, for instance by strategically arranging highlyimmunogenic epitopes of the HHV polypeptides discussed herein.

Linker Sequences. Linker sequences are used in the modified gBpolypeptide to replace the furin cleavage site in the extracellulardomain of the gB polypeptide. Linker sequences are also used in thefusion proteins to separate different components of the fusion protein.Thus, in certain embodiments, the amino terminal end of the linkersequence is joined by a peptide bond to a first polypeptide and thecarboxy terminal end of the linker sequence is joined by a peptide bindto a second polypeptide. The first and second polypeptides are each oneof the HHV fusion and host cell entry proteins or one of the HHVaccessory proteins. In certain embodiments, the first and secondpolypeptides are the same (e.g., gp350). In other embodiments, the firstand second polypeptides are different (e.g., gH and gL). Such a linkersequence joins the first polypeptide and the second polypeptide, incontrast to a first polypeptide and a second polypeptide that are joinedtogether without an intervening polypeptide sequence. It is understoodthat the linker sequence is not a sequence that naturally separates afirst and second polypeptide, if the first and second polypeptide happento naturally exist in combination together.

In one embodiment, the linker sequence is a polypeptide having 5-25amino acids, particularly a length of 6, 7, 8, 9, 10, 11, 12, 13, 14,15, 16, 17, 18, 19 or 20 amino acids. In another embodiment, the linkersequence is a polypeptide having 10-25 amino acids. The linker sequencepreferably comprises glycine and serine amino acids. In one embodiment,the linker sequence is 15 amino acids in length and has the amino acidsequence (Gly₄Ser)₃ (SEQ ID NO: 3).

Other suitable peptide linkers are those described in U.S. Pat. Nos.4,751,180, 4,935,233, and 5,073,627, each of which is herebyincorporated by reference in its entirety. A DNA sequence encoding adesired linker sequence may be inserted between, and in the same readingframe as, for example, DNA sequences encoding the first and secondpolypeptide using conventional techniques known in the art. For example,a chemically synthesized oligonucleotide encoding the linker may beligated between sequences encoding the first and second polypeptide.

Oligomerization Domains. Oligomerization domains are used in certainembodiments to make multimeric HHV polypeptides. Oligomerization domainsare stretches of amino acid residues that cause polypeptides comprisingthem to oligomerize, i.e., to form covalent and/or non-covalentassociations with another polypeptide comprising a corresponding orcognate oligomerization domain. Thus, two or more polypeptides are“oligomerized” if they are bound to each other via their oligomerizationdomains. Any oligomerization domain known in the art can be used.Examples include leucine zipper domains, complement C1q domains,α-helical coiled coil domains, thrombospondin domains, and fibritindomains. (See, Engel et al., Matrix Biol., 19(4):283-288, 2000). Thepolypeptides in an oligomer can have identical polypeptide sequences,similar polypeptide sequences, or different polypeptide sequences.

Homodimerization and homo-oligomerization refer to the association ofthe same polypeptide components to form dimers or oligomers.Heterodimerization and hetero-oligomerization refer to the associationof different polypeptides to form dimers or oligomers. Homo-oligomersthus comprise an association of multiple copies of a particularpolypeptide, while hetero-oligomers comprise an association of copies ofdifferent polypeptides. “Oligomerization,” “oligomerize,” and“oligomer,” with or without prefixes, are intended to encompass“dimerization,” “dimerize,” and “dimer.” Thus, in one embodiment, theoligomerization domain is a dimerization domain that mediates theself-association of two HHV polypeptides and/or two HHV fusion proteins.In another embodiment, the oligomerization domain is a trimerizationdomain that mediates the self-association of three HHV polypeptidesand/or three HHV fusion proteins. In another embodiment, theoligomerization domain is a tetramerization domain that mediates theself-association of four HHV polypeptides and/or four HHV fusionproteins. In one embodiment, the trimerization domain is fibritin motifor a eukaryotic GCN4 transcription factor motif or derivative thereof.

In one embodiment, the oligomerization domain comprises a leucine zipperdomain. Leucine zipper domains are peptides that promote oligomerizationof the proteins in which they are found. Leucine zippers were originallyidentified in several DNA-binding proteins (Landschulz et al., Science,240:1759, 1988), and have since been found in a variety of differentproteins. Among the known leucine zippers are naturally occurringpeptides and derivatives thereof that dimerize or trimerize. Forexample, the yeast GCN4 leucine zipper can be used to dimerizepolypeptides of interest. (Czerwinski et al., Transfusion, 35(2):137-44,1995; and O'Shea et al., Science, 243(4890):538-42, 1989). Otherexamples of leucine zipper domains suitable for producing solublemultimeric proteins are described in PCT application WO 94/10308, andthe leucine zipper derived from lung surfactant protein D (SPD)described in Hoppe et al. FEBS Lett. 344:191, 1994. The use of amodified leucine zipper that allows for stable trimerization of aheterologous protein fused thereto is described in Fanslow et al.,Semin. Immunol., 6:267, 1994.

In yet another embodiment, the oligomerization domain is a fibritintrimerization motif, particularly a bacteriophage fibritin trimerizationmotif, more particularly a fibritin trimerization domain frombacteriophage T4 (also called T4 foldon or foldon domain) or phage RB69or phage AR1 or a derivative thereof. The T4 fibritin trimerizationdomain and variants thereof are described in U.S. Pat. Nos. 6,911,205;8,147,843, and WO 01/19958, which are hereby incorporated by referencein their entirety.

Protein Complexes. In certain embodiments, the HHV polypeptidesdisclosed herein are present in the antigenic composition as a proteincomplex. For example, in certain embodiments, the HHV gB, gL, and gH arepresent in the antigenic composition as a protein complex. In otherembodiments, the HHV gH, gL, UL128, UL130, and UL131A polypeptides arepresent in the antigenic composition as a protein complex. In yetanother embodiment, the HHV gH, gL, and gO polypeptides are present inthe antigenic composition as a protein complex.

Proteins in the protein complex are typically linked by non-covalentprotein—protein interactions, including but not limited to hydrogenbonding and salt bridges. The protein complex has a quaternarystructure, corresponding to the arrangement or shape resulting from theassembly and interaction of the individual proteins, and, therefore, isuseful for inducing neutralizing antibodies against conformationepitopes on the HHV protein complex. In some embodiments, the proteincomplex, as used herein, does not refer to the native protein complex asit exists on the surface of a herpesvirus. Rather, the protein complexis formed by incubating the individual proteins in vitro, to create areconstructed protein complex.

Nucleic Acids, Cloning, and Expression Systems. The present disclosurefurther provides isolated nucleic acids encoding the disclosed monomericor multimeric HHV polypeptides. The nucleic acids may comprise DNA orRNA and may be wholly or partially synthetic or recombinant Reference toa nucleotide sequence as set out herein encompasses a DNA molecule withthe specified sequence and encompasses an RNA molecule with thespecified sequence in which U is substituted for T, unless contextrequires otherwise.

The present disclosure also provides constructs in the form of plasmids,vectors, phagemids, transcription or expression cassettes which compriseat least one nucleic acid encoding a monomeric or multimeric HHV fusionor host cell entry protein or a portion thereof. The disclosure furtherprovides a host cell which comprises one or more constructs as above.

Also provided are methods of making the monomeric or multimeric HHVpolypeptides encoded by these nucleic acids. The monomeric or multimericHHV polypeptides may be produced using recombinant techniques. Theproduction and expression of recombinant proteins is well known in theart and can be carried out using conventional procedures, such as thosedisclosed in Sambrook et al., Molecular Cloning: A Laboratory Manual(4th Ed. 2012), Cold Spring Harbor Press. For example, expression of thefusion protein may be achieved by culturing under appropriate conditionsrecombinant host cells containing the nucleic acid encoding themonomeric or multimeric HHV polypeptides. Following production byexpression a monomeric or multimeric HHV polypeptides may be isolatedand/or purified using any suitable technique, then used as appropriate.As discussed herein, under certain conditions, two or more the HHVfusion and host cell entry proteins and optionally one or more HHVaccessory proteins form a protein complex when incubated in vitro.

Systems for cloning and expression of a polypeptide in a variety ofdifferent host cells are well known in the art. Any protein expressionsystem compatible with the constructs disclosed in this application maybe used to produce the disclosed monomeric or multimeric HHVpolypeptides.

Suitable vectors can be chosen or constructed, so that they containappropriate regulatory sequences, including promoter sequences,terminator sequences, polyadenylation sequences, enhancer sequences,marker genes and other sequences as appropriate.

A further aspect of the disclosure provides a host cell comprising anucleic acid as disclosed herein. A still further aspect provides amethod comprising introducing such nucleic acid into a host cell. Theintroduction may employ any available technique. For eukaryotic cells,suitable techniques may include calcium phosphate transfection,DEAE-Dextran, electroporation, liposome-mediated transfection andtransduction using retrovirus or other virus, e.g., vaccinia or, forinsect cells, baculovirus. For bacterial cells, suitable techniques mayinclude calcium chloride transformation, electroporation andtransfection using bacteriophage. These techniques are well known in theart. (See, e.g., “Current Protocols in Molecular Biology,” Ausubel etal. eds., John Wiley & Sons, 2010). DNA introduction may be followed bya selection method (e.g., antibiotic resistance) to select cells thatcontain the vector.

gH/gL/UL128/UL130/UL131A. Recombinant nucleic acid constructs weredesigned to produce a HHV protein complex comprising gH, gL, UL128,UL130, and UL131A. In one embodiment, the recombinant nucleic acidconstruct comprises a first nucleic acid encoding a HHV gH polypeptide,a second nucleic acid encoding a HHV gL polypeptide, a third nucleicacid encoding a HHV UL128 polypeptide, a fourth nucleic acid encoding aHHV UL130 polypeptide, and a fifth nucleic acid encoding a HHV UL131Apolypeptide. In certain embodiments, a pentameric complex is formed whenthe recombinant nucleic acid is expressed in a host cell. In certainembodiments, none of the encoded polypeptides comprise a transmembranedomain or an intracellular domain. In certain embodiments, therecombinant nucleic acid comprises one or more internal ribosome entrycites (IRES) to facilitate expression of multiple proteins from a singletranscript. In certain embodiments, the recombinant nucleic acidcomprises a first IRES between the first and second nucleic acids, asecond IRES between the second and third nucleic acids, and/or a thirdIRES between the fourth and fifth nucleic acids. In certain embodiments,the recombinant nucleic acid comprises one or more promoter sequences tofacilitate expression of the HHV polypeptides. In certain embodimentsthe recombinant nucleic acid comprises a first promoter operativelylinked to the first nucleic acid and a second promoter operativelylinked to the third nucleic acid. In one embodiment, the promoter is aCMV promoter. In certain embodiments, the HHV is a betaherpesvirussubfamily member, including, for example, HCMV. A non-limiting,exemplary embodiment of such a recombinant nucleic acid is depicted inFIG. 13. Additional nucleic acid sequences can be included in such anucleic acid sequence to aid in purification, such as a proteinpurification tag (e.g., his-tag sequences) or a leader sequence topromote secretion from the host cell (e.g., immunoglobulin kappa lightchain leader sequences). In certain embodiments, the leader sequence isinserted in frame with each of the first, second, third, fourth, andfifth nucleic acid.

gH/gL/gO. Recombinant nucleic acid constructs were designed to produce aHHV complex comprising gH, gL, and gO. In one embodiment, therecombinant nucleic acid construct comprises a first nucleic acidencoding a HHV gH polypeptide, a second nucleic acid encoding a HHV gLpolypeptide, a third nucleic acid encoding a HHV gO polypeptide. Incertain embodiments, a trimeric complex is formed when the recombinantnucleic acid is expressed in a host cell. In certain embodiments, noneof the encoded polypeptides comprise a transmembrane domain or anintracellular domain. In certain embodiments, the recombinant nucleicacid comprises one or more internal ribosome entry cites (IRES) tofacilitate expression of multiple proteins from a single transcript. Incertain embodiments, the recombinant nucleic acid comprises an IRESbetween the first and second nucleic acids. In certain embodiments, therecombinant nucleic acid comprises one or more promoter sequences tofacilitate expression of the HHV polypeptides. In certain embodimentsthe recombinant nucleic acid comprises a first promoter operativelylinked to the first nucleic acid and a second promoter operativelylinked to the third nucleic acid. In one embodiment, the promoter is aCMV promoter. In certain embodiments, the HHV is a betaherpesvirussubfamily member, including, for example, HCMV. An exemplary embodimentof such a recombinant nucleic acid is depicted in FIG. 14. Additionalnucleic acid sequences can be included in such a nucleic acid sequenceto aid in purification, such as a protein purification tag (e.g.,his-tag sequences) or a leader sequence (e.g., immunoglobulin kappalight chain leader sequences). In certain embodiments, the leadersequence is inserted in frame with each of the first, second and thirdnucleic acid.

Vaccine Compositions. The combinations of monomeric and/or multimericHHV polypeptides and nucleic acids encoding the same that are describedin this application provide an improved platform for developing a HHVvaccine.

Thus, one aspect is directed to an antigenic composition as describedherein comprising two or more HHV fusion and host cell entry proteins(or nucleic acids encoding the same). In certain embodiments, thevaccine comprises virus like particles. In certain embodiments, theantigenic composition further comprises at least one pharmaceuticallyacceptable excipient, and optionally an adjuvant (hereinafter referredto as “vaccine composition”). In certain embodiments, the vaccinecomposition does not include an adjuvant.

In certain embodiments, the vaccine is a nucleic acid vaccine,comprising a nucleic acid encoding the two or more HHV fusion and hostcell entry proteins. In certain embodiments, the nucleic acid vaccine isa DNA vaccine. In other embodiments, the nucleic acid vaccine is an RNAvaccine. In certain embodiments, the nucleic acid vaccine is a viralvector vaccine.

The pharmaceutically acceptable excipient can be chosen from, forexample, diluents such as starch, microcrystalline cellulose, dicalciumphosphate, lactose, sorbitol, mannitol, sucrose, methyl dextrins;binders such as povidone, hydroxypropyl methylcellulose, dihydroxypropylcellulose, and sodium carboxylmethylcellulose; and disintegrantssuch as crospovidone, sodium starch glycolate, croscarmellose sodium,and mixtures of any of the foregoing. The pharmaceutically acceptableexcipient can further be chosen from lubricants such as magnesiumstearate, calcium stearate, stearic acid, glyceryl behenate,hygrogenated vegetable oil, glycerine fumerate and glidants such ascolloidal silicon dioxide, and mixtures thereof. In some embodiments,the pharmaceutically acceptable excipient is chosen frommicrocrystalline cellulose, starch, talc, povidone, crospovidone,magnesium stearate, colloidal silicon dioxide, sodium dodecyl sulfate,and mixtures of any of the foregoing. The excipients can beintragranular, intergranular, or mixtures thereof.

The vaccine composition can be formulated as freeze-dried or liquidpreparations according to any means suitable in the art. Non-limitingexamples of liquid form preparations include solutions, suspensions,syrups, slurries, and emulsions. Suitable liquid carriers include anysuitable organic or inorganic solvent, for example, water, alcohol,saline solution, buffered saline solution, physiological salinesolution, dextrose solution, water propylene glycol solutions, and thelike, preferably in sterile form. After formulation, the vaccinecomposition can be incorporated into a sterile container which is thensealed and stored at a low temperature (e.g., 4° C.), or it can befreeze dried.

The vaccine composition can be formulated in either neutral or saltforms. Pharmaceutically acceptable salts include the acid addition salts(formed with the free amino groups of the active polypeptides) and whichare formed with inorganic acids such as, for example, hydrochloric orphosphoric acids, or organic acids such as acetic, oxalic, tartaric,mandelic, and the like. Salts formed from free carboxyl groups can alsobe derived from inorganic bases such as, for example, sodium, potassium,ammonium, calcium, or ferric hydroxides, and such organic bases asisopropylamine, trimethylamine, 2-ethylamino ethanol, histidine,procaine, and the like.

The vaccine composition can optionally comprise agents that enhance theprotective efficacy of the vaccine, such as adjuvants. Adjuvants includeany compound or compounds that act to increase an immune response to thetwo or more HHV fusion and host cell entry proteins, thereby reducingthe quantity of proteins (or nucleic acid encoding the same) necessaryin the vaccine, and/or the frequency of administration necessary togenerate a protective immune response. Adjuvants can include forexample, emulsifiers, muramyl dipeptides, avridine, aqueous adjuvantssuch as aluminum hydroxide, chitosan-based adjuvants, and any of thevarious saponins, oils, and other substances known in the art, such asAmphigen, LPS, bacterial cell wall extracts, bacterial DNA, CpGsequences, synthetic oligonucleotides and combinations thereof (Schijnset al. (2000) Curr. Opin. Immunol., 12:456), Mycobacterial phlei (M.phlei) cell wall extract (MCWE) (U.S. Pat. No. 4,744,984), M. phlei DNA(M-DNA), and M. phlei cell wall complex (MCC). Compounds which can serveas emulsifiers include natural and synthetic emulsifying agents, as wellas anionic, cationic and nonionic compounds. Among the syntheticcompounds, anionic emulsifying agents include, for example, thepotassium, sodium and ammonium salts of lauric and oleic acid, thecalcium, magnesium and aluminum salts of fatty acids, and organicsulfonates such as sodium lauryl sulfate. Synthetic cationic agentsinclude, for example, cetyltrimethylammonium bromide, while syntheticnonionic agents are exemplified by glycerylesters (e.g., glycerylmonostearate), polyoxyethylene glycol esters and ethers, and thesorbitan fatty acid esters (e.g., sorbitan monopalmitate) and theirpolyoxyethylene derivatives (e.g., polyoxyethylene sorbitanmonopalmitate). Natural emulsifying agents include acacia, gelatin,lecithin and cholesterol.

Other suitable adjuvants can be formed with an oil component, such as asingle oil, a mixture of oils, a water-in-oil emulsion, or anoil-in-water emulsion. The oil can be a mineral oil, a vegetable oil, oran animal oil. Mineral oils are liquid hydrocarbons obtained frompetrolatum via a distillation technique, and are also referred to in theart as liquid paraffin, liquid petrolatum, or white mineral oil.Suitable animal oils include, for example, cod liver oil, halibut oil,menhaden oil, orange roughy oil and shark liver oil, all of which areavailable commercially. Suitable vegetable oils, include, for example,canola oil, almond oil, cottonseed oil, corn oil, olive oil, peanut oil,safflower oil, sesame oil, soybean oil, and the like. Freund's CompleteAdjuvant (FCA) and Freund's Incomplete Adjuvant (FIA) are two commonadjuvants that are commonly used in vaccine preparations, and are alsosuitable for use in the present invention. Both FCA and FIA arewater-in-mineral oil emulsions; however, FCA also contains a killedMycobacterium sp.

Immunomodulatory cytokines can also be used in the vaccine compositionsto enhance vaccine efficacy, for example, as an adjuvant. Non-limitingexamples of such cytokines include interferon alpha (IFN-α),interleukin-2 (IL-2), and granulocyte macrophage-colony stimulatingfactor (GM-CSF), or combinations thereof.

The vaccine composition can be prepared using techniques well known tothose skilled in the art including, but not limited to, mixing,sonication and microfluidation. The adjuvant can comprise from about 10%to about 80% (v/v) of the vaccine composition, more preferably about 20%to about 50% (v/v), and more preferably about 20% to about 30% (v/v), orany integer within these ranges.

The vaccine composition can be administered to any animal, andpreferably is a mammal such as a human, mouse, rat, hamster, guinea pig,rabbit, cat, dog, monkey, cow, horse, pig, and the like. Humans are mostpreferred.

Administration of the vaccine composition can be by infusion orinjection (e.g., intravenously, intramuscularly, intracutaneously,subcutaneously, intrathecal, intraduodenally, intraperitoneally, and thelike). The vaccine composition can also be administered intranasally,vaginally, rectally, orally, intratonsilar, or transdermally.Additionally, the vaccine composition can be administered by“needle-free” delivery systems.

The effective amount of the vaccine composition may be dependent on anynumber of variables, including without limitation, the species, breed,size, height, weight, age, overall health of the patient, the type offormulation, or the mode or manner or administration. The appropriateeffective amount can be routinely determined by those of skill in theart using routine optimization techniques and the skilled and informedjudgment of the practitioner and other factors evident to those skilledin the art. Preferably, a therapeutically effective dose of the vaccinecomposition described herein will provide the therapeutic preventivebenefit without causing substantial toxicity to the subject.

The vaccine composition can be administered to a patient on any scheduleappropriate to induce and/or sustain an immune response against the twoor more HHV fusion and host cell entry proteins. For example, patientscan be administered a vaccine composition as a primary immunization asdescribed and exemplified herein, followed by administration of asecondary immunization, or booster, to bolster and/or maintainprotective immunity.

The vaccine administration schedule, including primary immunization andbooster administration, can continue as long as needed for the patient,for example, over the course of several years, to over the lifetime ofthe patient. The frequency of primary vaccine and booster administrationand dose administered can be tailored and/or adjusted to meet theparticular needs of individual patients, as determined by theadministering physician according to any means suitable in the art.

The vaccine composition may be administered prophylactically (beforeexposure to the antigen or pathogen of interest) or therapeutically(after exposure to the antigen or pathogen of interest).

Methods of Inducing an Immune Response. In another aspect, two or moreHHV fusion and host cell entry proteins (or nucleic acid encoding thesame) can be used in a method of inducing an immune response orotherwise treating or preventing a HHV infection in a subject. Theimmune response can be induced in a naïve subject who has not previouslybeen exposed to HHV. Alternatively, the immune response can be inducedin a subject who has been previously exposed to HHV and used to enhancean existing immune response.

In one embodiment, the method of inducing an immune response comprisesadministering to a subject two or more HHV fusion and host cell entryproteins, as described herein, in an amount sufficient to induce animmune response against the two or more HHV fusion and host cell entryproteins in the subject. In another embodiment, the method of inducingan immune response comprises administering to a subject one or morenucleic acid constructs encoding the two or more HHV fusion and hostcell entry proteins, as described herein, in an amount sufficient toinduce an immune response against the two or more HHV polypeptides inthe subject. In certain embodiments, the method induces an additiveantibody response to the two or more HHV fusion and host cell entryproteins. In certain embodiments, the method induces a synergisticantibody response to the two or more HHV fusion and host cell entryproteins.

In these methods of inducing an immune response, the immune response canbe measured using routine methods in the art, such as those disclosed inthis application. These routine methods include, but are not limited to,measuring an antibody response, such as an antibody response directedagainst an HHV protein, and measuring cellular proliferation, including,for example, by measuring tritiated thymidine incorporation or cytokine(e.g., IFN-γ) production.

In certain embodiments, the method of treating or preventing an HHVinfection comprises administering to a subject a therapeuticallyeffective amount of two or more HHV polypeptides, as described herein,or one or more nucleic acid constructs encoding the same.

In these methods that comprise a step of administering two or more HHVfusion and host cell entry proteins, the proteins can be administeredsimultaneously or sequentially. In certain embodiments, the HHV proteinsthat make up the antigenic compositions disclosed herein areadministered simultaneously (concomitantly), for example, as part of thesame composition or as part of different compositions administered atthe same time. In other embodiments, the HHV proteins that make up theantigenic compositions disclosed herein are administered separately(sequentially), for example, administered as individual compositions atdifferent times. That is, the at least two HHV polypeptides in thecompositions can be simultaneously or separately administered to achievethe effects disclosed herein. Further, compositions can be administeredin one or more doses to achieve the desired result.

Typically, the subject is a human. In certain embodiments, the subjectis at risk of developing PTLD following a transplant, such as ahematopoietic stem cell or solid organ transplant. In certainembodiments, the subject suffers from a primary immunodeficiencysyndrome, including, for example, AIDS. In certain embodiments, thesubject is at risk of developing nasopharynegeal carcinoma. In certainembodiments, the subject has nasopharyngeal carcinoma.

Subjects in some embodiments concurrently receive one or more of ananti-CD20 antibody, anti-viral therapy, interferon alpha, radiotherapy,and/or chemotherapy. CD-20 antibody therapy and related biologics areknown in the art, as are radiotherapy and chemotherapy. Any of the knowntherapy regimens of these categories can be concurrently administered tothe subject in need thereof.

Passive Immunotherapy and Adoptive Transfer of Cell-Mediated Immunity.Passive immunotherapy methods for various indications are known in theart and have been employed in various forms for over 120 years. (See,Waldman, T. A., Nature Medicine, 9(3):269-277, 2003; and Chippeaux etal., J. Venom. Anim. Toxins Incl. Trop. Dis., 21:3, 2013; see alsoCasadevall et al., Clin. Infect. Dis., 21(1):150-61, 1995). The benefitsof passively transferring antibodies for inflammation, immunedeficiency, acute and chronic autoimmune diseases, and cancer is wellestablished. (Kivity et al., Clin. Rev. Allergy Immunol., 38:201-69,2010; and Toubi et al., Clin. Rev. Allergy Immunol., 29:167-72, 2005).Studies have documented multifunctional mechanisms of passivelytransferred antibodies, including mediation of humoral and cellularimmune responses through both its Fab and Fc portions withneutralization and enhanced clearance of pathogens. Passiveimmunotherapy is also sometimes referred to optionally as cell transfertherapy, immunoglobulin therapy, antiserum therapy, passive transfer, orpassive immunity. When immune cells are the immune components orneutralizing agent administered to the subject in need thereof, themethod is often referred to as adoptive transfer, adoptive cellulartherapy (ACT), or adoptive immunotherapy.

In passive immunotherapy, antibodies (or immunoglobulins) or otherimmune system components, i.e., agents that possess antigen neutralizingactivity, such as immune cells, are made outside of the subject beingadministered these components, typically made in a laboratory and/orproduced ex vivo by a second subject (or several other subjects). Insome embodiments, the immune system component administered to thesubject is a monoclonal antibody. In other embodiments, the immunecomponent is a polyclonal antibody. In still other embodiments, theimmune component is one or more immune cells. In all instances, theimmune component includes antibodies or cells that specificallyrecognize a target antigen, such as a target antigen present on an HHVfusion and host cell entry protein.

Having shown that various combinations of HHV fusion and host cell entryproteins induce high-titer neutralizing antibodies, it was contemplatedthat such high-titer neutralizing antibodies could be used to passivelytransfer immunity against HHV. Thus, antibodies generated by a subjectwho was immunized with two or more HHV fusion and host cell entryproteins, as described herein, can be harvested from the subject andisolated. The donor subject can be immunized with any combination of HHV(e.g., EBV, HCMV, HSV-1 or HSV-2, VZV, HHV-6, HHV-7, or KSVH) fusion andhost cell entry proteins as described herein to induce the high-titeranti-HHV antibodies.

In an EBV passive immunization or adoptive transfer embodiment, a donorsubject is immunized with, for example, a tetrameric EBV gp350 proteinand the induced high-titer neutralizing antibodies obtained therefromare employed in a passive transfer of immunity to an acceptor subjectwho benefits therefrom. In a further EBV embodiment, a donor subject isimmunized with, for example, a trimeric EBV gH/gL protein and theinduced high-titer neutralizing antibodies obtained therefrom areemployed in a passive transfer of immunity to an acceptor subject whobenefits therefrom. In another exemplary EBV embodiment, a donor subjectis immunized with, for example, a trimeric gB protein and the inducedhigh-titer neutralizing antibodies obtained therefrom are employed in apassive transfer of immunity to an acceptor subject who benefitstherefrom.

In an HCMV passive immunization or adoptive transfer embodiment, a donorsubject is immunized with, for example, a trimeric HCMV gB protein andthe induced high-titer neutralizing antibodies obtained therefrom areemployed in a passive transfer of immunity to an acceptor subject whobenefits therefrom. In a further HCMV embodiment, a donor subject isimmunized with, for example, a trimeric HCMV gH/gL protein and theinduced high-titer neutralizing antibodies obtained therefrom areemployed in a passive transfer of immunity to an acceptor subject whobenefits therefrom.

In an HSV passive immunization or adoptive transfer embodiment, a donorsubject is immunized with, for example, a trimeric HSV gB protein andthe induced high-titer neutralizing antibodies obtained therefrom areemployed in a passive transfer of immunity to an acceptor subject whobenefits therefrom. In a further HSV embodiment, a donor subject isimmunized with, for example, a trimeric HSV gH/gL protein and theinduced high-titer neutralizing antibodies obtained therefrom areemployed in a passive transfer of immunity to an acceptor subject whobenefits therefrom.

In a VZV passive immunization or adoptive transfer embodiment, a donorsubject is immunized with, for example, a trimeric HSV gB protein andthe induced high-titer neutralizing antibodies obtained therefrom areemployed in a passive transfer of immunity to an acceptor subject whobenefits therefrom. In a further VZV embodiment, a donor subject isimmunized with, for example, a trimeric VZV gH/gL protein and theinduced high-titer neutralizing antibodies obtained therefrom areemployed in a passive transfer of immunity to an acceptor subject whobenefits therefrom.

In a KSHV passive immunization or adoptive transfer embodiment, a donorsubject is immunized with, for example, a trimeric KSHV gB protein andthe induced high-titer neutralizing antibodies obtained therefrom areemployed in a passive transfer of immunity to an acceptor subject whobenefits therefrom. In a further KSHV embodiment, a donor subject isimmunized with, for example, a trimeric KSHV gH/gL protein and theinduced high-titer neutralizing antibodies obtained therefrom areemployed in a passive transfer of immunity to an acceptor subject whobenefits therefrom.

Immunization with the two or more HHV fusion and host cell entryproteins can be simultaneous, in multiple doses, or in staggered doses,as long as the desired neutralizing activity is obtained in the donorsubject. These antibodies induced in the donor subject can then beadministered to another subject in need thereof. Alternatively, thehigh-titer neutralizing antibodies against the HHV fusion and host cellentry proteins can be obtained from one or more blood, serum, or plasmasamples that have been selected for the high-titer antibodies. Incertain embodiments, the one or more blood, serum, or plasma samples areobtained from a human donor.

The immune components can also be obtained synthetically, as inmonoclonal antibodies, produced in tissue culture or by animals, or canbe obtained from another, donor, subject who is either seropositive forimmune components specifically recognizing the desired antigen, or whohas been exposed to the antigen and thereby has developedseropositivity. In certain embodiments, the donor subject possesses ahigh degree of responsiveness to the antigen, i.e., possess a highconcentration, or high titer, of the antigen-neutralizing immunecomponents (e.g., antibodies or immune cells). These immune componentsare then extracted from the donor subject, or obtained from tissueculture or animals, purified or otherwise manipulated in the laboratoryas needed to avoid possible graft vs. host reactions or other adversereactions, and then administered to the subject in need thereof.

Steps for implementing a passive immunotherapy or adoptive transferprotocol or methodology involve, in some embodiments, first identifyinga donor subject possessing a high neutralizing activity against HHV. Incertain embodiments, high titer anti-HHV antibodies or immune cells areobtained from blood, serum, and/or plasma samples collected from thedonor subject. These immune components are then transferred to a secondsubject in need thereof, in order to induce an immunoprotective effectin the second subject, thereby preventing or treating an HHV infection.The second subject can be infected with an HHV, or susceptible toinfection with HHV. The antibodies can be optionally extracted and/orpurified prior to administration to the subject in need thereof.Further, in other embodiments, optionally the donor subject ishistocompatible with the subject in need thereof, such that blood,serum, and/or plasma may be administered to the subject in need thereof.In some embodiments, the blood, serum, and/or plasma is obtained from ahuman donor.

The term “high-titer” as used herein, refers to an antibody having atiter specific for the desired HHV polypeptide in an amount that is2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold,12-fold, 14-fold, 16-fold, 18-fold, 20-fold, 25-fold, or in someembodiments, as much as 30-fold higher than an average titer fromunselected plasma, serum, or blood samples from a general population ofdonor subjects and that comprises antibodies possessing the samespecificity. In certain embodiments, the donor subject has been exposedto the HHV polypeptide antigen and is not seronegative or naïve. Incertain embodiments, the donor subject, or donor subjects, has/have beenadministered two or more of the HHV fusion and host cell entry proteins,in order to generate a high-titer antibody response in the donorsubject(s). High-titer antibodies can be identified or selected usingthe methods described in this application (e.g., Raji B cellneutralization assay or a HeLa cell neutralization assay) or any knownmethod in the art. Antibody titers can be determined by variousart-recognized screening methods or by the methods disclosed in thisapplication. In one embodiment, high-titer antibodies are identified orselected using a Raji B cell neutralization assay or a HeLa cellneutralization assay, as described, for example, in the examples of thisapplication. In certain embodiments, the HeLa cell neutralization assaycomprises, infecting HeLa cells with labeled EBV (e.g., EBV with afluorescent label, such as green fluorescent protein) to yieldEBV-infected HeLa cells, incubating the blood, plasma or serum samplewith the EBV-infected HeLa cells, analyzing the neutralization activityof the blood, plasma, or serum sample (e.g., using flow cytometry or anELISpot assay) and optionally calculating the IC₅₀ of the blood, plasma,or serum sample.

The subject in need thereof is a subject who is naïve (seronegative forHHV), immunocompromised, or otherwise susceptible to infection, oralready infected with one or more HHV. In certain embodiments, thesubject is administered high titer anti-EBV antibodies and is at risk ofdeveloping post-transplantation lymphoproliferative disorder (PTLD)following hematopoietic stem cell or solid organ transplantation, or hasor is at risk of developing nasopharyngeal carcinoma (NPC), Burkittlymphoma, Hodgkin's lymphoma, non-Hodgkin's lymphoma, gastric carcinoma,severe infectious mononucleosis, chronic active EBV infection, multiplesclerosis, systemic lupus erythematosus, or rheumatoid arthritis. Incertain embodiments, the subject is at risk of developing PTLD, forexample, following hematopietic stem cell or solid organ transplant. Incertain embodiments, the subject is at risk of developing nasopharyngealcarcinoma.

In another embodiment, the subject is administered high titer anti-HCMVantibodies and is a pregnant woman, a transplantation patient, a patientwho is immunosuppressed during chemotherapy or radiotherapy, or apatient infected with human immunodeficiency virus (HIV). In anotherembodiment, the subject is administered high titer anti-HSV-1 or HSV-2antibodies and is at risk of developing encephalitis caused by HSV-1 orHSV-2 infection, or is a pregnant woman with active HSV-2 or HSV-1infection and/or HSV encephalitis. In another embodiment, the subject isadministered high titer anti-ZVZ antibodies and is at risk of developingZoster (shingles) or Varicella (chickenpox). In a further embodiment,the subject is administered high titer anti-KSHV antibodies and is atrisk of developing KSHV-associated Kaposi's sarcoma, primary effusionlymphoma, multicentric Cattleman's disease, KSHV-associated inflammatorycytokine syndrome, or KSHV immune reconstitution inflammatory syndrome.

In another embodiment, the subject in need thereof is concurrentlyreceiving anti-viral therapy, anti-CD20 antibody compositions,interferon-alpha, radiotherapy, and/or chemotherapy.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art. Although methods and materials similar or equivalent to thosedescribed herein can be used in the practice or testing of the presentinvention, suitable methods and materials are described below. Allpublications, patent applications, patents, and other referencesmentioned herein are incorporated by reference in their entirety. Incase of conflict, the present specification, including definitions, willcontrol. In addition, the materials, methods, and examples areillustrative only and not intended to be limiting.

EXAMPLES 1. Epstein Bar Virus (EBV) Example 1.1—Production of EBV gH andEBV gL Polypeptides

To recombinantly produce EBV gH and gL polypeptides, coding sequencesfor EBV gH and gL were downloaded from the NCBI website, referencesequence NC_009334.1, including EBV gH nucleotides 129454 through131574, and EBV gL nucleotides 98500 through 98913. The gL sequenceencoding amino acids 23-137 was used, and the signal peptide at aminoacids 1-22 was replaced with an IgG κ leader sequence. The gH sequencecoding corresponding to amino acids 19-678 was linked to the 3′ end ofthe gL sequence and separated by a 15-amino acid linker (Gly₄Ser)₃ (SEQID NO: 3) sequence. (See representative schematic in FIG. 1). A foldontrimerization domain coding sequence derived from T4 phage fibritin (seee.g., U.S. Pat. Nos. 6,911,205; 8,147,843, and WO 01/19958) was linkedto the 3′ end of gH, followed by a His₆ (SEQ ID NO: 49) coding sequence.DNA coding for the trimeric gH/gL was synthesized and cloned into thevector pOptiVEV (Invitrogen, Carlsbad, Calif., USA), and the sequenceverified by sequencing. The monomeric EBV gH/gL construct was made byPCR amplification of EBV gH/gL without the foldon trimerization codingsequence, and cloned into pOptiVEV. The sequence was verified bysequencing.

Chinese Hamster Ovary (CHO) cells (strain DG44, Invitrogen, Carlsbad,Calif., USA) were transfected with the resultant pOptiVEV-gH/gLconstructs and positive cells were selected with gradually increasedconcentrations of methotrexate (MTX), up to 4 μM. Selected CHO cellswere loaded into “Fibercell” cartridges (FiberCell Systems, Frederick,Md., USA) for protein production. Supernatants were concentrated andpurified using cobalt affinity purification (Thermo Fisher Scientific,Waltham, Mass., USA). Recombinant proteins were further purified by sizeexclusion chromatography using Sephadex® G200 column or Superose® 6Increase 10/300 GL column (GE Healthcare, Little Chalfont, UK).

Western blot analysis of trimeric gH/gL polypeptides using an anti-His₆(SEQ ID NO: 49) mAb or an anti-EBV gH/gL mAb (clone E1D1, gift from Dr.L. M. Hutt-Fletcher, Louisiana State University Health Sciences Center,Shreveport, La., USA), under reducing conditions that disrupt the nativeoligomers, revealed a molecular weight (MW) band of about 90 kiloDaltons(kDa), consistent with the predicted size of monomeric gH/gL (FIG. 2A).Under non-reducing conditions, a MW band of about 270 kDa was observed,consistent with predicted size of trimeric gH/gL (FIG. 2A).

Example 1.2—Production of EBV gB Polypeptides

To recombinantly produce EBV gB polypeptides, the coding sequence forEBV gB was downloaded from the NCBI website, corresponding to referencesequence NC_009334.1, nucleotides 157775 through 160348. The sequenceencoding the extracellular domain of EBV gB (amino acids 23-732 of wildtype EBV) was used to design the construct for trimeric gB expression.The signal peptide, corresponding to amino acids 1-22, was replaced withan IgG κ leader sequence, and the coding sequence of the furin cleavagesite (RRRRD) (SEQ ID NO: 50) between amino acids 427 (L) and 434 (A) wasreplaced with a 15-amino acid (Gly₄Ser)₃ (SEQ ID NO: 3) linker sequence(FIG. 1). A His₆ (SEQ ID NO: 49) sequence was linked to the 3′ end forprotein purification. All the following steps were as described abovefor EBV gH/gL.

Western blot analysis under fully reducing conditions using an anti-His₆(SEQ ID NO: 49) mAb or an anti-gB mAb (Virusys Corp., Taneytown, Md.,USA) demonstrated that the EBV gB protein was the predicted size of themonomeric form (about 80 kDa) (FIG. 2B). Under modified non-reducingconditions that allows for detection of the native form of EBV gBprotein, a uniform band with the predicted size of a trimeric EBV gB(about 240 kDa) was observed (FIG. 2B).

Example 1.3—Production of EBV gp350 Polypeptides

EBV gp350 polypeptides were expressed as previously described (see, Cuiet al., Vaccine, 31:3039-45, 2013; see also WO 2014/018858, which ishereby incorporated by reference in its entirety). Briefly, an EBVmonomeric gp350 construct was made by PCR amplification of the gp350cDNA, strain B95-8. A sequence encoding amino acids 1-470 was clonedwith an IgG κ leader sequence added to the 5′ end and His₆ (SEQ ID NO:49) coding sequence added to the 3′ end. The tetrameric gp350 constructwas made by ligation of a second gp350 fragment (1-470) to the 3′ end ofthe monomeric gp350 construct (without His₆ (SEQ ID NO: 49)). The secondgp350 fragment has a (Gly₄Ser)₃ (SEQ ID NO: 3) linker at the 5′ end anda leucine zipper sequence at the 3′ end for homodimerization, followedby His₆ (SEQ ID NO: 49) sequence for protein purification (FIG. 1).Monomeric and tetrameric gp350 DNA were cloned into pOptiVEV, and theirsequences verified by sequencing. All of the following steps were asdescribed above for EBV gH/gL.

Western blot analysis using anti-gp350 mAbs, clone 2L10 (MerckMillipore, Billerica, Mass., USA), 72A1 (ATCC, Manassas, Va., USA), oran anti-His₆ (SEQ ID NO: 49) mAb, under denatured (reducing) condition,revealed a single ˜100 kDa band corresponding to monomeric gp350, and asingle band at about 200 kDa consistent with a gp350 dimer, resultingfrom the dissociation of the two gp350 dimers that form the tetramericgp350 (FIG. 2C). Under native (non-reducing) condition, a single band atabout 100 kDa was revealed, consistent with monomeric gp350, and asingle band at about 400 kDa was observed, consistent with thetetrameric gp350 (FIG. 2C).

Example 1.4—Induction of EBV Immune Response in Rabbits

The obtained EBV polypeptides were examined in vaccine preparations fortheir ability to induce an immune response in rabbits. In this study andthe example following this example, the level of immune response wasdetermined by the level of EBV polypeptide-specific antibodies found inserum. In this study, groups of five male New Zealand white rabbits, 12to 15 weeks old, were immunized subcutaneously with 25 μg of each of theEBV antigens, including tetrameric EBV gp350, trimeric EBV gH/gL, ortrimeric EBV gB, versus monomeric EBV gp350, or monomeric EBV gH/gL. Theantigens were adsorbed to aluminum hydroxide (alum; 0.25 μg alum/mg ofprotein) and mixed with 50 μg of a 12-mer phosphorothioate-modified CpGoligodeoxynucleotide (ODN) with optimization for use in rabbits(hereinafter, ODN 2007, TCGTCGTTGTCGTTTTGTCGTT (SEQ ID NO: 51)) prior toinjection (see, Ioannou et al., Vaccine, 21:4368-72, 2003). The activityof ODN 2007 was confirmed by its ability to stimulate IgM secretion whenadded to rabbit splenocytes (Id.). Rabbits immunized with alum andCpG-ODN alone served as the negative control. Rabbits were immunized onday 0, day 21, and day 42. Serum samples were taken before initialimmunization, and 10 days following each immunization.

Sera were obtained 10 days after the last immunization for measurementof IC₅₀ neutralization titers in cultures of Raji B lymphoma cells andgreen fluorescent protein (GFP)-labeled EBV. IC₅₀ values shown in FIG. 3represent the reciprocal serum titer that generates 50% EBVneutralization. EBV infection was measured by flow cytometry. Asillustrated in FIG. 3, tetrameric gp350 and trimeric gH/gL elicitedsignificantly (*p<0.05) higher IC₅₀ titers than their monomericcounterparts. Of note, significant differences (p<0.05) in IC₅₀ titerswere also observed among the multimeric proteins with gH/gL(IC₅₀=506)>gB (IC₅₀=89)>gp350 (IC₅₀=22).

Thus, as illustrated in FIG. 3, each of the five EBV polypeptidesinduced augmented IgG responses following the first boosterimmunization, including monomeric gp350 (FIG. 3, left panel, opencircles) and monomeric gH/gL (FIG. 3, middle panel, open circles).Further significant augmentation in serum IgG titers followed the secondbooster immunization. Tetrameric EBV gp350 (FIG. 3, left panel, closedcircles) induced >20-fold serum gp350-specific IgG titers relative tomonomeric EBV gp350 (FIG. 3, left panel, open circles) following thefirst and second booster immunizations. Trimeric EBV gH/gL (FIG. 3,middle panel, closed circles) induced greater than 30-fold and greaterthan 90-fold increases in serum gH/gL-specific IgG titers following theprimary immunization and the first booster immunization, respectively,with the titers equalizing by the second booster immunization. Thesedata are consistent with a previous study performed in mice usingtetrameric and monomeric gp350 (Cui et al., Vaccine, 31:3039-45, 2013),that showed that multimerization of tetrameric fusion EBV gp350polypeptides induce marked increases in immunogenicity.

Example 1.5—EBV Antibody Titers Induced by Monomeric gH/gL, TrimericgH/gL, and Trimeric gB, as Compared to Titers Induced by Monomeric andTetrameric Gp350

Determination of serum in vitro EBV-neutralizing titers, using Rajicells (EBV-positive human Burkitt lymphoma cell line), were performed asdescribed (Sashihara et al., Virology, 391:249-56, 2009). Briefly,GFP-EBV (B95-8/F) was prepared by transfection of 293/2089 cells withplasmids p509 and p2670 expressing EBV BZLF1 and EBV BALF4, respectively(gift from Dr. Jeffrey I. Cohen, N.I.H., Bethesda, Md., USA) (Neuhierlet al., Proc. Natl. Acad. Sci. U.S.A., 99:15036-41, 2002; and Delecluseet al., Proc. Natl. Acad. Sci. U.S.A, 95:8245-50, 1998). Serial serumdilutions were mixed for 2 h with GFP-EBV in 96-well plates, followed byaddition of Raji cells for 1 additional hour. Cells were then washed andre-cultured in medium alone for 3 days, fixed in paraformaldehyde andanalyzed by flow cytometry for GFP+ Raji cells. The serum dilution thatinhibited infectivity by 50% (IC₅₀), based on reduction of the number ofGFP+ cells, was calculated by non-linear regression analysis using Prism6 software (GraphPad Software, Inc., La Jolla, Calif., USA). AnEBV-neutralizing anti-gp350 mAb (72A1) was used as a positive control.Pre-immune sera and sera from rabbits immunized with alum+CpG-ODN aloneserved as negative controls. For determination of serum neutralizingtiters using peripheral blood naïve human B cells, naïve human B cellsisolated from peripheral blood of healthy donors were incubated withGFP-EBV and cultured in RPMI 1640 medium containing 100 ng/ml IL-4(BioLegend, San Diego, Calif., USA) and 1 μg/ml CD40 antibody (R&DSystems, Minneapolis, Minn., USA).

As illustrated in FIG. 4A, tetrameric EBV gp350 induced significantlyhigher IC₅₀ titers (the effective dilution of antibody that inhibitedinfectivity by 50%) than monomeric EBV gp350 (IC₅₀22 versus less than 5,respectively). Of note, trimeric gH/gL induced significantly higher IC₅₀titers than monomeric gH/gL (IC₅₀ 506 versus 107, respectively), titerlevels that are markedly and significantly higher than that induced bytetrameric gp350. Similarly, trimeric EBV gB induced significantlyhigher IC₅₀ titers (IC₅₀ 89) than tetrameric gp350 (IC₅₀ 22) and wascomparable to that elicited by monomeric gH/gL (IC₅₀ 107). Compared tomonomeric gp350, which has been previously tested in a phase II clinicaltrial, trimeric gH/gL, monomeric gH/gL, trimeric gB, and tetramericgp350 elicited greater than 100-, 20-18-, and 4-fold higher IC₅₀ titersrespectively. Similar data was obtained from sera that were pooled fromeach of the groups shown in FIG. 4A, utilizing GFP-EBV and naïveperipheral blood human B cells from healthy donors for determination ofEBV neutralization titers (FIG. 4B), except that monomeric andtetrameric gp350 showed slightly higher IC₅₀ titers compared to thosecalculated using Raji cells (FIG. 4A). Thus, EBV gH/gL and EBV gBproteins, like EBV gp350, elicit antibodies in rabbits that block EBVentry into Raji Burkitt lymphoma and naïve peripheral human B cells.However, EBV gH/gL and EBV gB proteins appear to be significantly morepotent on a per weight basis than EBV gp350.

Example 1.6—Immunization of Rabbits with EBV Trimeric gB and MonomericgH/gL

New Zealand white rabbits, 12-15 weeks old, were immunizedsubcutaneously with a combination of EBV trimeric gB and monomericgH/gL, each 25 μg adsorbed to aluminum hydroxide (alum; 0.25 μg alum/mgprotein) and mixed with 100 μg of a 12-mer phosphorothioate-modifiedCpG-ODN (TCATAACGTTCC (SEQ ID NO: 52)) optimized for rabbits (Ioannou etal., Vaccine, 21:4368-72, 2003). Rabbits were immunized on day 0, day21, and day 42, and serum samples were taken before initialimmunization, and 10 days following each immunization. EBVneutralization assay based on flow cytometric analysis of GFP-labeledEBV entry into Raji Burkitt lymphoma B cells was used to measure serumEBV neutralizing titers that inhibit infectivity of 50% of Raji B cells(IC₅₀). Administering both EBV trimeric gB and monomeric gH/gL yieldedsynergistic results as compared to administering the individual EBVproteins. More specifically, at day 52, rabbits immunized with the EBVtrimeric gB and monomeric gH/gL demonstrated 16-fold and 14-fold higherEBV neutralization activity compared to the rabbits immunized with EBVtrimeric gB or monomeric gH/gL alone, respectively (FIG. 5).

Example 1.7—EBV Neutralization In Vitro with Anti-Sera Combinations

Different combinations of the sera obtained from rabbits immunized withtrimeric EBV gB, monomeric EBV gH/gL, or monomeric EBV gp350, wereanalyzed for in vitro EBV-neutralizing titers using Raji cells. TrimericgB+monomeric gH/gL sera, trimeric gB+monomeric gp350 sera, monomericgH/gL+monomeric gp350 sera, and trimeric gB+monomeric gH/gL+monomericgp350 sera, all showed more than 2-fold increased EBV neutralizationactivity compared to the sum of the neutralization activity ofindividual protein immune serum, clearly demonstrating synergisticeffects in EBV neutralization activity (FIG. 6B).

Different combinations of the sera from rabbits immunized with EBVtrimeric gB, trimeric gH/gL or tetrameric gp350 were also analyzed forin vitro EBV-neutralizing titers using Raji cells. Trimeric gB+trimericgH/gL sera, trimeric gH/gL+tetrameric gp350 sera, and trimericgB+trimeric gH/gL+tetrameric gp350 sera showed EBV neutralizationactivity comparable to the sum of the neutralization activity ofindividual protein immune serum (FIG. 6B). Trimeric gB+tetrameric gp350sera showed more than 2-fold increased EBV neutralization activitycompared to the sum of the neutralization activity of individual proteinimmune serum, demonstrating synergism (FIG. 6A).

The synergistic results obtained when certain EBV proteins were combinedwas not expected. The additive results obtained when other EBV proteinswere combined were similarly unexpected given the potential fordiminished antibody responses due to vaccine or immune interference.

Example 1.8—Passive Transfer of Immunity Against EBV in NOG Mice

In this study, mice were challenged with live EBV to determine whetheranti-sera from the rabbits exposed to EBV polypeptides, above, canprotect the mice from EBV infection, i.e. through a passive immunitytransfer model. NOD/Shi-scid/IL-2Rγ^(null) (NOG) mice are anart-recognized humanized mouse model of EBV infection, mirroring keyaspects of EBV infection in humans (Yajima et al., J. Infect. Dis.,198:673-82, 2008). NOG mice are immunodeficient, lacking mature T, B,and natural killer cells. The immune system of NOG mice can bereconstituted with a functional human immune system to generatehumanized NOG (hu-NOG) mice by transplanting hematopoietic stem cell(HSC) from human cord blood (Yajima et al., J. Infect. Dis., 198:673-82,2008). Inoculation of the mice with about 1×10³ TD₅₀ (50% transformingdose) of EBV causes B cell lymphoproliferation with histopathologicalfindings and latent EBV gene expression similar to that observed inimmunocompromised humans, and mortality by 10 weeks post-infection andare thus considered a useful model for EBV-driven PTLD in humans.(Dittmer et al., Curr. Opin. Virol., 14:145-50, 2015).

Hu-NOG mice are still defective in eliciting specific human IgGresponses to protein antigens and thus not appropriate for directvaccination studies (Seung et al., J. Infect. Dis., 208 Suppl 2:S155-9,2013), necessitating passive immunization studies to determine aprotective role for EBV-specific antibodies. In this regard, an earlierstudy reported that 85% of SCID mice injected i.p. with peripheral bloodmononuclear cells (PBMCs) from an EBV-seropositive healthy blood donordeveloped B cell lymphomas over a 150-day period. However, tumorformation was prevented by weekly treatments with 2 different commercialIVIg preparations (not specifically selected for high EBV neutralizingactivity) or by purified IgG from EBV-seropositive, but not seronegativedonors. (Abedi et al., Int. J. Cancer, 71:624-9, 1997).

In this study, hu-NOG mice were derived by intravenous injection ofhuman CD34(+) HSCs isolated from cord blood (about 1×10⁴ to 1.2×10⁵cells/female mouse at 6-10-week-old). After the human hemato-immunesystem was reconstituted, four groups (n=4) of hu-NOG mice were injectedwith 300 μl i.p. of the day 52 pooled sera from rabbits immunized withtetrameric EBV gp350, trimeric EBV gH/gL, trimeric EBV gB, or control(adjuvant (alum+CpG-ODN) alone). Two hours following i.p. injection ofrabbit sera, hu-NOG mice were infected intravenously with about 1×10³TD₅₀ of EBV (AKATA Burkitt lymphoma cell line), a dose that induces Bcell lymphoproliferation and fatality within or at about 10 weeks.(Yajima et al., J. Infect. Dis., 198:673-682, 2008).

Seventy-five (75) days after EBV infection, the three hu-NOG micereceiving sera from alum+CpG-ODN-injected rabbits all died, whereas allthree mice receiving trimeric gB-specific pooled antisera survived after132 days of EBV infection (FIG. 7A). One hu-NOG mouse receivingtetrameric gp350-specific pooled antisera survived for 119 days, and onehu-NOG mouse receiving trimeric gH/gL-specific pooled antisera survived132 days (FIG. 7A). Compared to the hu-NOG mice receiving control(alum+CpG-ODN sera), the copy number of EBV from multiple organs of themice receiving trimeric gH/gL-specific pooled antisera or tetramericgp350-specific pooled antisera was significantly lower relative to serafrom rabbits injected with alum+CpG-ODN alone in multiple organs (FIG.7B). The effects of gB-specific pooled antisera on EBV organ involvementwere not reported as the experiment was ongoing. Hu-NOG mice receivinggB-, gH/gL-, or gp350-specific pooled antisera also showed markedlylower EBV DNA blood levels relative to the adjuvant control, though thehu-NOG mice receiving trimeric gB-specific pooled antisera had higherEBV load in peripheral blood compared to the mice receiving tetramericgp350-specific pooled antisera or trimeric gH/gL-specific pooledantisera (FIG. 7 C).

2. Human Cytomegalovirus (HCMV) Example 2.1—Production of Trimeric HCMVgB

The above results with EBV fusion/cell entry proteins show unexpectedlyhigh levels of antibody induction when the EBV polypeptides werecombined. Based on these novel findings, we expected to obtain similarresults when combining fusion/cell entry proteins from other HHVfamilies, such as HCMV. To this end, similar studies were designed toshow that the observations made in the EBV studies can be extended toother HHV family members, like HCMV.

For HCMV, a coding sequence for HCMV gB was obtained from the NCBIwebsite, reference sequence NC_006273.2, strain Merlin, nucleotides82066 through 84789. The DNA sequence encoding for amino acids 23-750 ofHCMV gB (corresponding to the extracellular domain of gB) was used, andthe signal peptide (corresponding to amino acids 1-22) was replaced withan IgG κ leader sequence. To make a trimeric version of the gBpolypeptide, the coding sequence for the cleavage site, RTKRS (SEQ IDNO: 53) between amino acids 456 (N) and 462 (T), was replaced with a15-amino acid (Gly₄Ser)₃ (SEQ ID NO: 3) linker sequence (FIG. 8A). AHis₆ (SEQ ID NO: 49) sequence was added to the 3′ end for proteinpurification. The DNA coding for the gB protein was synthesized, clonedinto pOptiVEV (Invitrogen, Carlsbad, Calif., USA), and the sequenceverified by sequencing. CHO cells (strain DG44; Invitrogen, Carlsbad,Calif., USA) were stably transfected with pOptiVEC-gB, and positivecells selected with increasing concentrations of methotrexate up to 4μM. Supernatants were concentrated for affinity purification using acobalt column (Thermo Fisher Scientific, Waltham, Mass., USA).

Purified proteins were analyzed by electrophoresis on 3-8% NuPAGETris-Acetate Mini-Gels, under reducing condition. Purified HCMV gB wasboiled for 10 minutes in lithium dodecyl sulfate sample loading buffercontaining 50 mM DTT, blotted with anti-gB monoclonal antibody 2F12(Virusys Corp., Taneytown, Md., USA) or LS-C64457 (LifeSpan BioSciences,Inc., Seattle, Wash., USA), and both showed 120 kDa band correspondingto monomer (FIG. 9A). Purified HCMV gB was also analyzed by PAGE undermodified non-reducing condition (mixed protein with Lithium dodecylsulfate sample buffer without DTT, resolved on 3-8% PAGE in nativerunning buffer), and blotted with anti-gB monoclonal antibody LS-C64457,which showed a band with molecular weight of about 360 kDa, consistentwith trimeric gB (FIG. 9B).

Example 2.2—Production of Monomeric and Trimeric HCMV gH/gL Polypeptides

Likewise, the coding sequences for HCMV gH and gL were obtained from theNCBI website, reference sequence NC_006273.2, strain Merlin, gHnucleotides 109224 through 111452, gL nucleotides 165022 through 165858.The construct for trimeric HCMV gH/gL expression was synthesized usingMacVector (MacVector, Inc., Apex, N.C., USA) and following the designused to express trimeric EBV gH/gL. The gL sequence encoding amino acids31-278 was used, and the signal peptide corresponding to amino acids1-30 was replaced with an IgG κ leader sequence. The gH sequenceencoding amino acids 24-718 was linked to the 3′ end of gL and separatedby a 15-amino acid linker (Gly₄Ser)₃ (SEQ ID NO: 3) sequence. A foldontrimerization domain coding sequence derived from T4 phage fibritin waslinked to the 3′ end of gH, followed by a His₆ (SEQ ID NO: 49) codingsequence for protein purification. DNA coding for the trimeric gH/gL wassynthesized, cloned into pOptiVEV (Invitrogen, Carlsbad, Calif., USA),and the sequence was verified by sequencing. The monomeric HCMV gH/gLconstruct was made by PCR amplification of the trimeric HCMV gH/gLwithout the foldon trimerization domain coding sequence, cloned intopOptiVEV, and the sequence verified by sequencing.

Chinese Hamster Ovary (CHO) cells (strain DG44) (Invitrogen) were stablytransfected with the obtained pOptiVEC-gH/gL constructs using Free-styleMax reagent (Invitrogen, Carlsbad, Calif., USA), and positivetransformants were selected with gradually increased concentration ofmethotrexate up to 4 μM. Supernatants were concentrated and purifiedusing Cobalt affinity purification (Thermo Fisher Scientific, Waltham,Mass., USA), and analyzed by Western blot using both an anti-His₆ (SEQID NO: 49) antibody and anti HCMV gH/gL antibody (Santa Cruz Biotech,Dallas, Tex., USA). Under reducing conditions, the Western blot showedmonomeric gH/gL as a band of about 110 kDa (FIG. 9C), and undernon-reducing conditions, the trimeric gH/gL appeared as a band of about330 kDa (FIG. 9D).

Example 2.3—Induction of HCMV IgG with Trimeric gB and Monomeric gH/gL

Having generated the desired HCMV polypeptide constructs, comparativestudies were conducted to determine whether multimeric polypeptidesand/or various polypeptide combinations generated substantially greaterimmune response than monomeric polypeptides. Thus, seven groups of fivemale New Zealand white rabbits, 12 to 15 weeks old were immunizedsubcutaneously with 25 μg of a single HCMV envelope protein or acombination of HCMV envelope proteins (25 μg of each protein in thecombination). Twenty-five μg of each protein was adsorbed to aluminumhydroxide (alum; 0.25 μg alum/mg protein) and mixed with 25 μg ofCpG-ODN with known activity in rabbits (ODN 2007 having the sequenceTCGTCGTTGTCGTTTTGTCGTT (SEQ ID NO: 51)). The HCMV proteins/combinationsused were monomeric gH/gL, monomeric UL128/UL130/UL131A, monomeric gB(Sino gB), trimeric gB, monomeric gH/gL+monomeric UL128/UL130/UL131A,trimeric gB+monomeric gH/gL, or trimeric gB+monomeric gH/gL+monomericUL128/UL130/UL131A. Rabbits were immunized on Day 0, Day 21, and Day 42,and serum samples were taken before initial immunization, and at days10, 31, 52, and 72 following immunization. Serum titers ofantigen-specific IgG against live HCMV were determined using fibroblasts(cell line MRC-5, ATCC, Manassas, Va., USA) and epithelial cells (cellline ARPE-19, ATCC, Manassas, Va., USA). Recombinant trimeric HCMV gBand monomeric HCMV gH/gL proteins were incubated together at roomtemperature of 30 minutes and were found to induce high titers ofprotein-specific IgG (FIG. 11).

HCMV neutralization assay. Pooled Day 52 and Day 72 sera from the fiverabbits in each cohort immunized with a single HCMV envelope protein ora combination of HCMV envelope proteins were either heat inactivated at56° C. for 30 minutes to eliminate complement activity or not heattreated. Serum HCMV neutralizing antibody titers were determined usingELISpot assay. Each serum sample was prepared 1:2 serial dilutions withculture medium in in quadruplicates. Each dilution was mixed with anequal volume of culture medium containing HCMV strain AD169WT131,incubated for 4 hours at 37° C. then added to the wells of 96-wellplates containing ARPE-19 (epithelial line, ATCC, Manassas, Va., USA) orMRC-5 (fibroblast line, ATCC, Manassas, Va., USA) monolayers andcultured overnight at 37° C., with 5% CO₂. Cells were fixed withabsolute ethanol, rehydrated and blocked with 5% normal horse serum inPBS, followed by incubation with anti-IE1 monoclonal antibody MAB810(Merck Millipore, Burlington, Mass., USA), goat anti-mouse secondaryantibody (Jackson ImmunoResearch Labs, West Grove, Pa., USA) each for 1hour, and VECTASTAIN ABC reagent (Vector Labs, Burlingame, Calif., USA)for 30 minutes. Plates were washed three times with 0.05 Tween 20 in PBSbetween each step, and TrueBlue (Sigma-Aldrich, St. Louis, Mo., USA) wasadded for color development. The plates were scanned and analyzed usinga CTL-ImmunoSpot® S6 Micro Analyzer (ImmunoSpot, Cellular TechnologyLimited, Cleveland, Ohio, USA). Fifty percent inhibitory concentration(IC₅₀) values and standard errors of the means were calculated usingGraphPad Prism6 software by plotting the means of triplicate values foreach serum dilution against log serum concentration, calculating thebest fit four-parameter equation for the data, and interpolating theserum dilution at the mid-point of the curve as the IC₅₀ neutralizingtiter.

FIG. 12A shows the HCMV neutralization activity analyzed using ARPE-19cells, where the rabbit immune sera were not heat inactivatedImmunization of rabbits with monomeric UL128/UL130/UL131A elicitedlittle HCMV neutralization activity, yielding an IC₅₀ titer of less than10 (FIG. 12A) Immunization with monomeric gH/gL elicited low levelcomplement-dependent HCMV neutralization activity (IC₅₀ of 190.9, FIG.12A). Immunization of rabbits with the combination of monomericgH/gL+monomeric UL128/UL130/UL131A elicited 3-fold highercomplement-dependent HCMV neutralization activity (IC₅₀ of 676.9) thanthe sum of the HCMV neutralization elicited by monomeric gH/gL ormonomeric UL128/UL130/UL131A alone (FIG. 12A) Immunization of rabbitswith monomeric gB (Sino gB) elicited moderate complement-dependent HCMVneutralization activity (IC₅₀ 528.0), and trimeric gB elicited 4-foldhigher complement-dependent HCMV neutralization activity related tomonomeric gB (IC₅₀ of 2168.8). FIG. 12A Immunization with a combinationof trimeric gB and monomeric gH/gL elicited 2-fold highercomplement-dependent HCMV neutralization activity (IC₅₀ of 4299.2) thanthe sum of the HCMV neutralization elicited by trimeric gB and monomericgH/gL individually, demonstrating a synergistic effect (FIG. 12A)Immunization of rabbits with a combination of trimeric gB, monomericgH/gL and monomeric UL128/UL130/UL131A elicited 5-fold highercomplement-dependent HCMV neutralization activity (IC₅₀ of 10910.8) thanthe sum of the HCMV neutralization elicited by trimeric gB, monomericgH/gL and monomeric UL128/UL130/UL131A individually, demonstrating asynergistic effect (FIG. 12A). The complement-dependent HCMVneutralization activity elicited by the immunization with combination oftrimeric gB, monomeric gH/gL, and monomeric UL128/UL130/UL131A is20-fold higher than that of the monomeric gB (Sino gB), whichdemonstrated 50% efficacy in prevention of HCMV infection in phase IIclinical trials.

The HCMV neutralization activity analyzed using fibroblast cell lineMRC-5, where the rabbit immune sera were heat inactivated at 56° C. for30 minutes to eliminate complement activity, is shown in FIG. 12BImmunization of rabbits with monomeric gB (Sino gB) elicited low levelsof complement-independent HCMV neutralization activity (IC₅₀ 103.5), andtrimeric gB elicited 20-fold higher complement-independent HCMVneutralization activity as compared to monomeric gB (IC₅₀ of 2185.2,FIG. 12B). Immunization of rabbits with monomeric gH/gL also elicitedlow level complement-independent HCMV neutralization activity (IC₅₀ of167.7). In contrast, immunization with a combination of trimeric gB andmonomeric gH/gL elicited 5-fold higher complement-independent HCMVneutralization activity (IC₅₀ of 12299.4) than the sum of the HCMVneutralization activity elicited by trimeric gB and monomeric gH/gLindividually, demonstrating a synergistic effect (FIG. 12B). Thecomplement-independent HCMV neutralization activity elicited by theimmunization with a combination of trimeric gB and monomeric gH/gL wasmore than 100-fold higher than monomeric gB (Sino gB), whichdemonstrated 50% efficacy in prevention of HCMV infection in phase IIclinical trials.

Example 2.4—In Vitro Neutralization Assays Using HCMV gB and gH/gLAnti-Sera

Serum HCMV neutralizing antibody titers were determined using an ELISpotassay. Serum samples were combined, and then divided by 1:2 serialdilutions with culture medium in triplicates. Each dilution was mixedwith an equal volume of culture medium containing 200 pfu of HCMV strainAD169^(WT131), incubated for 3 h at 37° C., then added to the wells of96-well plates containing MRC-5 monolayers and cultured overnight at 37°C., with 5% CO₂. Cells were fixed with absolute ethanol, rehydrated, andblocked with 1% BSA in PBS, followed by incubation with anti-IE1monoclonal antibody MAB810 (Millipore), biotin-labeled goat anti-mousesecondary antibody, and ABC reagent (Vector Laboratories) each for 1 h.Plates were washed three times with 0.05% Tween® 20 in PBS between eachstep, and TrueBlue was added for color development. The plates werescanned and analyzed using a CTL-ImmunoSpot® S6 Micro Analyzer (CellularTechnology Limited, Cleveland, Ohio). Fifty percent inhibitoryconcentration (IC₅₀) values and standard errors of the means werecalculated using GraphPad Prism7 software by plotting the means oftriplicate values for each serum dilution against log serumconcentration, calculating the best fit four-parameter equation for thedata, and interpolating the serum dilution at the mid-point of the curveas the IC₅₀ neutralizing titer.

The in vitro HCMV neutralization results obtained using pooled immunesera from rabbits immunized with monomeric HCMV gB, trimeric HCMV gB,monomeric HCMV gH/gL, and in vitro combinations thereof are provided inFIGS. 15-20. Multimerizing the HCMV polypeptides significantly enhancedthe neutralizing activity of antibodies generated against themultimerized polypeptides, as compared to a monomeric version of thepolypeptide. For example, the IC₅₀ of monomeric HCMV gB was 91.94compared to 2283 for trimeric HCMV gB (FIGS. 15 and 16). Combining HCMVgB immune sera and HCMV gH/gL immune sera unexpectedly induced higherHCMV neutralizing activity than the sum of the neutralizing activityinduced by each of the proteins individually, demonstrating synergism.For example, the IC₅₀ of the in vitro combination of monomeric HCMV gBimmune sera and monomeric gH/gL immune sera was 836.4 (FIG. 18), ascompared to an IC₅₀ of 91.94 and 169.6, respectively for each ofproteins individually (FIGS. 15 and 17). Similarly, the IC₅₀ of the invitro combination of trimeric HCMV gB immune sera and monomeric gH/gLimmune sera was 3093 (FIG. 19), as compared to an IC₅₀ of 2283 and 169.6(FIGS. 16 and 17, respectively for each of the proteins individually.These synergistic results are summarized in FIG. 20.

Thus, as with EBV, these comparative tests demonstrate that combiningHCMV fusion/cell entry proteins (e.g., gB and gH/gL) unexpectedlyenhances HCMV neutralization activity in vivo Immunization of rabbitswith a combination of HCMV trimeric or monomeric gB and monomeric gH/gLelicited significantly higher HCMV neutralization activity than the sumof individual proteins, demonstrating unexpected synergistic effects.

Example 2.5—Production of HCMV Monomeric and Trimeric UL128/130/131Polypeptides

In an effort to further characterize the possibilities of generatingheightened antibody titers by administering antigen compositionscomprising HHV polypeptides, the HCMV proteins UL128, UL130, and UL131were recombinantly produced. Briefly, the coding sequences for HCMVUL128 were obtained from the NCBI website, reference sequenceGQ121041.1, strain Towne, nucleotides 175653 through 176410. Codingsequences for HCMV UL130 and UL131A were also obtained from the NCBIwebsite, reference sequence NC_006273.2, strain Merlin, UL130nucleotides 176984 through 177628, and UL131A nucleotides 177649 through177802 joined to nucleotides 177911 through 178146. UL128 from strainTowne was used because the UL128 from strain Merlin has a mutation andis not functional. The construct for trimeric UL128-UL130-UL131Aexpression was designed using MacVector. The UL128 sequence encodingamino acids 28-171, UL130 sequence encoding amino acids 26-214, andUL131A sequence encoding amino acids 19-129, were linked by a 15-aminoacid linker (Gly₄Ser)₃ (SEQ ID NO: 3) between each coding sequence (FIG.10). A foldon trimerization domain coding sequence derived from T4 phagefibritin was linked to the 3′ end of UL131A, followed by a His₆ (SEQ IDNO: 49) coding sequence, and an IgGκ leader sequence was placed 5′ tothe UL128 sequence for secretion of recombinant protein (FIG. 10). DNAcoding for the trimeric UL128-UL130-UL131A was synthesized, cloned intopOptiVEV (Invitrogen, Carlsbad, Calif., USA), and the sequence wasverified. The monomeric UL128-UL130-UL131A construct was made by PCRamplification of trimeric UL128-UL130-UL131A without the foldontrimerization domain coding sequence, cloned into pOptiVEV, and thesequence was verified.

CHO cells (strain DG44, Invitrogen, Thermo Fisher Scientific, Carlsbad,Calif., USA) were stably transfected with the resultantpOptiVEC-UL128-UL130-UL131A construct using the Free-style Max reagent(Invitrogen, Carlsbad, Calif.), and positive transfectants were selectedwith gradually increased concentrations of methotrexate, up to 4 μM.Supernatants were concentrated and purified using Cobalt affinitypurification (Thermo Fisher Scientific, Waltham, Mass., USA). Westernblot analysis of the supernatants from CHO cells transfected with themonomeric UL128-UL130-UL131A construct using anti-His₆ (SEQ ID NO: 49)and anti-UL128 antibodies exhibited a band of about 57 kDa, consistentwith monomeric UL128/UL130/UL131A (FIG. 9E).

Example 2.6—Production of HCMV Pentameric gH/gL/UL128/130/131 Complex

The coding sequences for HCMV gH, gL, UL128, UL130 and UL131A wereobtained from the NCBI website. A construct for pentameric complexgH/gL/UL128/UL130/UL131A expression was designed using MacVector and isdepicted in FIG. 13. The construct includes a gL sequence encoding aminoacids 31-278, a gH sequence encoding amino acids 24-718, where thesignal peptide of both sequences were replaced with an IgG κ leadersequence. The EV71 Internal Ribosome Entry Site (IRES) sequence wasinserted between the sequences of gH and gL, and a His₆ (SEQ ID NO: 49)encoding sequence was attached to the 3′ end of gH for proteinpurification. The signal peptides of UL128, UL130, and UL131A were alsoreplaced with an IgG κ leader sequence, and the UL128 sequence encodingamino acids 28-171, UL130 sequence encoding amino acids 26-214, andUL131A sequence encoding amino acids 19-129, were linked together byinsertion of the EV71 IRES sequence between each. The UL128, UL130, andUL131A were driven by a second CMV promoter, which was placed 5′ end ofUL128, and 3′ end of gH-His₆ (SEQ ID NO: 49) coding sequence. HCMV gLand gH were driven by a first CMV promoter derived from vector pOptiVEC.

DNA coding for the pentameric complex gH/gL/UL128/UL130/UL131A will besynthesized, cloned into pOptiVEV (Invitrogen), and verified. CHO cells(strain DG44; Invitrogen) will be transfected withpOptiVEC-gH/gL/UL128/UL130/UL131A, and positive transformants can beselected with increasing concentrations of methotrexate up to 4 μM,using the procedures already outlined above for similar constructs.

Example 2.7—Production of HCMV gH/gL/gO Complex

As with the other HCMV constructs discussed above, the coding sequencesfor HCMV gH, gL were also obtained from the NCBI website, and the codingsequences for HCMV gO was also obtained from the NCBI website, referencesequence NC_006273.2, strain Merlin, gO nucleotides 107430 through108848. The construct for gH/gL/gO complex expression was designed usingMacVector and is depicted in FIG. 14, including the gL sequence encodingamino acids 31-278 and the gH sequence encoding amino acids 24-718. Thesignal peptides of both sequences were replaced with an IgGκ leadersequence. The EV71 Internal Ribosome Entry Site (IRES) sequence wasinserted between the gH and gL sequences, and a His₆ (SEQ ID NO: 49)encoding sequence was attached to the 3′ end of gH for proteinpurification. The signal peptide of gO was also replaced with an IgG κleader sequence, and the gO sequence coding amino acids 31-466 wasdriven by the second CMV promoter, which was placed 5′ end of gO, and 3′end of gH-His₆ (SEQ ID NO: 49) coding sequence. HCMV gH and gL weredriven by the first CMV promoter derived from vector pOptiVEC.

DNA coding for the gH/gL/gO complex will be synthesized and cloned intopOptiVEV as previously described. Stable CHO transformants will bepurified and analyzed with size exclusion chromatography and multi-anglelight scattering (SEC-MALS).

Example 2.8—Immunization of Mice with HCMV Trimeric gB and Monomeric gB

Six groups of 7- to 10-week old Balb/c mice (n=5) were immunized by theintraperitoneal (i.p.) route with 1 μg, 5 μg, or 25 μg of HCMV trimericgB or 1 μg, 5 μg, or 25 μg HCMV monomeric gB (Sino gB, Sino BiologicalInc., China). Antigen was adsorbed to aluminum hydroxide (alum; 0.25 μgalum/mg protein) and mixed with 25 μg of a 30-merphophorothioate-modified CpG-ODN (AAAAAAAAAAAAAACGTTAAAAAAAAAAAA (SEQ IDNO: 54)) optimized for mice. Mice immunized with only alum+CpG-ODNserved as negative controls. Mice were immunized on day 0, day 21, andday 42, and serum samples were taken before initial immunization, 10days following each immunization, and at day 63. Individual mouse serumsamples were analyzed for titers of gB-specific IgG by ELISA, and invitro neutralizing activity using fibroblasts (MRC-5) and epithelialcells (ARPE-19).

HCMV neutralization assay. Sera from mice immunized with monomeric ortrimeric gB were either heat inactivated at 56° C. for 30 minutes toeliminate complement activity or not heat treated. Serum HCMVneutralizing antibody titers were determined using ELISpot assay. Eachserum sample was prepared 1:2 serial dilutions with culture medium intriplicates. Each dilution was mixed with an equal volume of culturemedium containing HCMV strain AD169WT131, incubated for 4 hours at 37°C. and then added to the wells of 96-well plates containing MRC-5(fibroblast line, ATCC, Manassas, Va., USA) monolayers and culturedovernight at 37° C., with 5% CO₂. Cells were fixed with absoluteethanol, rehydrated, and blocked with 5% normal horse serum in PBS,followed by incubation with anti-IE1 monoclonal antibody MAB810 (MerckMillipore, Burlington, Mass., USA), goat anti-mouse secondary antibody(Jackson ImmunoResearch Labs, West Grove, Pa., USA) each for 1 hour, andVECTASTAIN ABC reagent (Vector Labs, Burlingame, Calif., USA) for 30minutes. Plates were washed three times with 0.1% Tween 20 in PBSbetween each step, and TrueBlue (Sigma-Aldrich, St. Louis, Mo., USA) wasadded for color development. The plates were scanned and analyzed usinga CTL-ImmunoSpot® S6 Micro Analyzer (ImmunoSpot, Cellular TechnologyLimited, Cleveland, Ohio, USA). Fifty percent inhibitory concentration(IC₅₀) values and standard errors of the means were calculated usingGraphPad Prism6 software by plotting the means of triplicate values foreach serum dilution against log serum concentration, calculating thebest fit four-parameter equation for the data, and interpolating theserum dilution at the mid-point of the curve as the IC₅₀ neutralizingtiter.

Monomeric and trimeric HCMV gB were directly compared side-by-side forelicitation of total serum titers of antigen-specific IgG. As shown inFIG. 21A, each group of the HCMV proteins induced augmented serum IgGresponses following the first booster immunization, and furthersignificant augmentation in serum IgG titers following the secondbooster immunization. Trimeric HCMV gB induced 5-fold to 11-fold higherserum titers of gB-specific antibody IgG titers relative to monomericHCMV gB after the first and second immunization, with greaterdifferences observed at the lower doses. The difference of HCMV gBspecific IgG titers elicited by trimeric and monomeric HCMV gB decreasedafter the third immunization, with less differences observed at thehigher doses. Five μg of trimeric HCMV gB elicited optimal antigenspecific IgG response. 25 μg of trimeric HCMV gB elicited slightlyhigher gB specific IgG titers, but not significantly different comparedto that of 5 μg of HCMV trimeric gB.

Using the MRC-5 fibroblast cell line, immune sera from mice immunizedwith trimeric HCMV gB that was heat inactivated at 56° C. for 30 minutes(to eliminate complement activity), demonstrated 50-fold higher HCMVneutralization activity against HCMV strain AD169wt131 compared to thatof immune sera from mice immunized with monomeric HCMV gB (FIG. 21B).The non-heat inactivated sera from mice immunized with monomeric HCMV gB(FIG. 21C) demonstrated 6-fold higher HCMV neutralization activitycompared to heat inactivated sera (FIG. 21B), whereas the non-heatinactivated sera from mice immunized with trimeric gB demonstrated 2 to3-fold higher HCMV neutralization activity compared to heat inactivatedsera. Without heat inactivation, the HCMV neutralization activityagainst HCMV strain AD169wt131 elicited by trimeric HCMV gB was 20-foldhigher than that of monomeric HCMV gB, suggesting that monomeric HCMV gBinduces a more complement-dependent response (FIG. 21C). CytoGam®, acommercial cytomegalovirus CMV-IgIV immunoglobulin containing hightiters of HCMV neutralizing antibody derived from the plasma of HCMVseropositive healthy donors (CSL Behring, King of Prussia, Pa., USA)showed much lower HCMV neutralization activity against HCMV strainAD169wt131 relative to trimeric gB. Using the MRC-5 cell line, 10 mg/mlCytoGam® demonstrated about one-thirtieth of the complement-independentHCMV neutralization activity of the sera from mice immunized withtrimeric HCMV gB. Heat inactivation has no effect on CytoGam®, whichmade its complement-dependent HCMV neutralization activity even lowercompared to non-heat inactivated sera from mice immunized with trimericHCMV gB or monomeric HCMV gB.

1. An antigenic composition comprising at least two human herpesviruspolypeptides or one or more nucleic acids encoding the at least twohuman herpesvirus polypeptides, wherein the antigenic compositioncomprises at least a first human herpesvirus polypeptide and at least asecond human herpesvirus polypeptide, wherein the first humanherpesvirus polypeptide comprises a monomeric or multimeric glycoproteinB (gB) polypeptide comprising an extracellular domain of humanherpesvirus gB; and the second human herpesvirus polypeptide comprises amonomeric or multimeric glycoprotein gH/glycoprotein gL (gH/gL)heterodimer comprising a gL polypeptide and a gH polypeptide comprisingan extracellular domain of human herpesvirus gH.
 2. The composition ofclaim 1, wherein the human herpes virus is human cytomegalovirus (HCMV),Herpes Simplex Virus-1 (HSV-1), Herpes Simplex Virus-2 (HSV-2),Varicella-Zoster Virus (VZV), Epstein-Barr Virus (EBV), Human HerpesVirus 6 (HHV-6), Human Herpes Virus 7 (HHV-7), or Kaposi Sarcoma-relatedHerpes Virus (KSHV).
 3. The composition of claim 1, wherein the gBpolypeptide and/or the gH polypeptide each further comprises acorresponding gB and/or gH intracellular domain, respectively.
 4. Thecomposition of claim 3, wherein the extracellular domain is fused to theintracellular domain via a polypeptide linker sequence.
 5. Thecomposition of claim 4, wherein the polypeptide linker sequence is about6 to about 70 amino acids in length, or wherein the peptide linker isabout 15 amino acids in length.
 6. The composition of claim 1 whereinthe first herpesvirus protein does not form a fusion protein with thesecond human herpesvirus protein.
 7. (canceled)
 8. The composition ofclaim 1, wherein the gB polypeptide is multimeric.
 9. (canceled)
 10. Thecomposition of claim 1, wherein the gB polypeptide is monomeric, dimericor trimeric and the gH/gL heterodimer is monomeric.
 11. The compositionof claim 1, wherein the at least two human herpesvirus polypeptides areHCMV polypeptides.
 12. The composition of claim 11, wherein thecomposition further comprises an HCMV glycoprotein O (gO) polypeptide.13. The composition of claim 11, wherein the composition furthercomprises an HCMV unique long 128 (UL128) polypeptide, an HCMV uniquelong 130 (UL130) polypeptide, an HCMV unique long 131A (UL131A)polypeptide, and optionally an HCMV glycoprotein M (gM) polypeptide,and/or an HCMV glycoprotein N (gN) polypeptide.
 14. The composition ofclaim 1, wherein the at least two human herpesvirus polypeptides arehuman EBV polypeptides. 15.-19. (canceled)
 20. The composition of claim14, wherein the gB polypeptide is trimeric gB, and wherein the gHpolypeptide and gL polypeptide form a monomeric or trimeric gH/gLheterodimer. 21.-22. (canceled)
 23. The composition of claim 20, furthercomprising a human EBV glycoprotein 42 (gp42) polypeptide, BDFL2polypeptide, and/or a human EBV BMRF-2 polypeptide.
 24. The compositionof claim 1, wherein the at least two human herpesvirus polypeptides arehuman HSV-1 or HSV-2 polypeptides.
 25. The composition of claim 24,wherein the gB polypeptide is monomeric, dimeric, or trimeric, andoptionally wherein the at least two human herpesvirus polypeptidescomprise a monomeric gH/gL heterodimer formed by the gH polypeptide andthe gL polypeptide and a monomeric gB polypeptide.
 26. The compositionof claim 25, further comprising an HSV-1 or HSV-2 glycoprotein D (gD)polypeptide, wherein the gD polypeptide is monomeric, dimeric, trimeric,or tetrameric.
 27. The composition of claim 1, wherein the at least twohuman herpesvirus polypeptides are human VZV polypeptides.
 28. Thecomposition of claim 27, wherein the gB polypeptide is monomeric,dimeric, or trimeric, and optionally wherein the at least two humanherpesvirus polypeptides comprise a monomeric gH/gL heterodimer formedby the gH polypeptide and the gL polypeptide and a monomeric gBpolypeptide.
 29. The composition of claim 28, further comprising one ormore of a human VZV glycoprotein C (gC) polypeptide, human glycoproteinE (gE) polypeptide, and human VZV glycoprotein I (gI) polypeptide. 30.The composition of claim 1, wherein the at least two human herpesviruspolypeptides are human HHV-6 or HHV-7 polypeptides.
 31. The compositionof claim 30, wherein wherein the gB polypeptide is monomeric, dimeric,or trimeric, and optionally wherein the at least two human herpesviruspolypeptides comprise a monomeric gH/gL heterodimer formed by the gHpolypeptide and the gL polypeptide and a monomeric gB polypeptide. 32.The composition of claim 1, wherein the at least two human herpesviruspolypeptides are human KSHV polypeptides.
 33. The composition of claim32, wherein the gB polypeptide is monomeric, dimeric, or trimeric, andoptionally wherein the at least two human herpesvirus polypeptidescomprise a monomeric gH/gL heterodimer formed by the gH polypeptide andthe gL polypeptide and a monomeric gB polypeptide.
 34. The compositionof claim 33, further comprising one or more of a human KSHV glycoproteinM (gM) polypeptide, a human KSHV glycoprotein N (gN) polypeptide, ahuman KSHV Open Reading Frame 68 (ORF68) polypeptide, and a human KSHVglycoprotein K8.1 polypeptide.
 35. The composition of claim 1, whereinthe one or more nucleic acids are in a viral vector that permitsexpression of the at least two human herpesvirus polypeptides.
 36. Thecomposition of claim 1, further comprising a pharmaceutically acceptableexcipient and/or an adjuvant.
 37. A method for preventing or treating ahuman herpesvirus infection in a subject comprising administering to thesubject a therapeutically effective amount of the composition ofclaim
 1. 38. A method for inducing immunity to a human herpesvirus in asubject comprising administering to the subject a therapeuticallyeffective amount of the composition of claim
 1. 39. The method of claim37, wherein the subject is at risk of developing post-transplantationlymphoproliferative disorder (PTLD) following hematopoietic stem cell orsolid organ transplantation and suffers from a primary immunodeficiencysyndrome.
 40. The method of claim 37, wherein the at least two humanherpesvirus polypeptides in the composition are administeredsequentially or concurrently. 41.-93. (canceled)